Differential positioning reference signal reporting within co-located cells

ABSTRACT

Disclosed are techniques for wireless positioning. In an aspect, a user equipment (UE) receives a plurality of downlink positioning reference signals (DL-PRS) transmitted by a corresponding plurality of cells, wherein the plurality of cells is grouped into one or more groups, wherein each of the one or more groups is associated with one or more attributes, and wherein each cell of each of the one or more groups has the same values of the one or more attributes, reports, to a positioning entity, at least one baseline positioning measurement for at least one representative cell of at least one group of the one or more groups based on DL-PRS transmitted by the at least one representative cell, and reports, to the positioning entity, differential positioning measurements for cells of the at least one group based on the at least one baseline positioning measurement.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present Application for Patent claims the benefit of U.S.Provisional Application No. 63/032,379, entitled “DIFFERENTIALPOSITIONING REFERENCE SIGNAL REPORTING WITHIN CO-LOCATED CELLS,” filedMay 29, 2020, assigned to the assignee hereof, and expresslyincorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

Aspects of the disclosure relate generally to wireless communications.

2. Description of the Related Art

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G and 2.75G networks), a third-generation (3G) high speeddata, Internet-capable wireless service and a fourth-generation (4G)service (e.g., Long Term Evolution (LTE) or WiMax). There are presentlymany different types of wireless communication systems in use, includingcellular and personal communications service (PCS) systems. Examples ofknown cellular systems include the cellular analog advanced mobile phonesystem (AMPS), and digital cellular systems based on code divisionmultiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), the Global System for Mobilecommunications (GSM), etc.

A fifth generation (5G) wireless standard, referred to as New Radio(NR), calls for higher data transfer speeds, greater numbers ofconnections, and better coverage, among other improvements. The 5Gstandard, according to the Next Generation Mobile Networks Alliance, isdesigned to provide data rates of several tens of megabits per second toeach of tens of thousands of users, with 1 gigabit per second to tens ofworkers on an office floor. Several hundreds of thousands ofsimultaneous connections should be supported in order to support largesensor deployments. Consequently, the spectral efficiency of 5G mobilecommunications should be significantly enhanced compared to the current4G standard. Furthermore, signaling efficiencies should be enhanced andlatency should be substantially reduced compared to current standards.

SUMMARY

The following presents a simplified summary relating to one or moreaspects disclosed herein. Thus, the following summary should not beconsidered an extensive overview relating to all contemplated aspects,nor should the following summary be considered to identify key orcritical elements relating to all contemplated aspects or to delineatethe scope associated with any particular aspect. Accordingly, thefollowing summary has the sole purpose to present certain conceptsrelating to one or more aspects relating to the mechanisms disclosedherein in a simplified form to precede the detailed descriptionpresented below.

In an aspect, a method of wireless positioning performed by a userequipment (UE) includes receiving a plurality of downlink positioningreference signals (DL-PRS) transmitted by a corresponding plurality ofcells, wherein the plurality of cells is grouped into one or moregroups, wherein each of the one or more groups is associated with one ormore attributes, and wherein each cell of each of the one or more groupshas the same values of the one or more attributes; reporting, to apositioning entity, at least one baseline positioning measurement for atleast one representative cell of at least one group of the one or moregroups based on DL-PRS transmitted by the at least one representativecell; and reporting, to the positioning entity, differential positioningmeasurements for cells of the at least one group based on the at leastone baseline positioning measurement.

In an aspect, a user equipment (UE) includes a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: receive, via the at least one transceiver, a plurality ofdownlink positioning reference signals (DL-PRS) transmitted by acorresponding plurality of cells, wherein the plurality of cells isgrouped into one or more groups, wherein each of the one or more groupsis associated with one or more attributes, and wherein each cell of eachof the one or more groups has the same values of the one or moreattributes; report, to a positioning entity, at least one baselinepositioning measurement for at least one representative cell of at leastone group of the one or more groups based on DL-PRS transmitted by theat least one representative cell; and report, to the positioning entity,differential positioning measurements for cells of the at least onegroup based on the at least one baseline positioning measurement.

In an aspect, a user equipment (UE) includes means for receiving aplurality of downlink positioning reference signals (DL-PRS) transmittedby a corresponding plurality of cells, wherein the plurality of cells isgrouped into one or more groups, wherein each of the one or more groupsis associated with one or more attributes, and wherein each cell of eachof the one or more groups has the same values of the one or moreattributes; means for reporting, to a positioning entity, at least onebaseline positioning measurement for at least one representative cell ofat least one group of the one or more groups based on DL-PRS transmittedby the at least one representative cell; and means for reporting, to thepositioning entity, differential positioning measurements for cells ofthe at least one group based on the at least one baseline positioningmeasurement.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a user equipment(UE), cause the UE to: receive a plurality of downlink positioningreference signals (DL-PRS) transmitted by a corresponding plurality ofcells, wherein the plurality of cells is grouped into one or moregroups, wherein each of the one or more groups is associated with one ormore attributes, and wherein each cell of each of the one or more groupshas the same values of the one or more attributes; report, to apositioning entity, at least one baseline positioning measurement for atleast one representative cell of at least one group of the one or moregroups based on DL-PRS transmitted by the at least one representativecell; and report, to the positioning entity, differential positioningmeasurements for cells of the at least one group based on the at leastone baseline positioning measurement.

Other objects and advantages associated with the aspects disclosedherein will be apparent to those skilled in the art based on theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 illustrates an example wireless communications system, accordingto aspects of the disclosure.

FIGS. 2A and 2B illustrate example wireless network structures,according to aspects of the disclosure.

FIGS. 3A, 3B, and 3C are simplified block diagrams of several sampleaspects of components that may be employed in a user equipment (UE), abase station, and a network entity, respectively, and configured tosupport communications as taught herein.

FIG. 4A is a diagram illustrating an example frame structure, accordingto aspects of the disclosure.

FIG. 4B is a diagram illustrating an example uplink frame structure,according to aspects of the disclosure.

FIG. 5 illustrates an example wireless communications system, accordingto aspects of the disclosure.

FIG. 6 is a diagram of an example physical layer procedure forprocessing positioning reference signals (PRS) transmitted on multiplebeams, according to aspects of the disclosure.

FIG. 7 illustrates an example flow for position estimation, according toaspects of the disclosure.

FIG. 8 illustrates an example flow for selecting times of arrival (TOAs)to improve positioning accuracy, according to aspects of the disclosure.

FIG. 9 illustrates a scenario for pruning TOAs, according to aspects ofthe disclosure.

FIG. 10 illustrates an example method for determining the location of aUE, according to aspects of the disclosure.

FIG. 11 illustrates an example method of wireless positioning, accordingto aspects of the disclosure.

DETAILED DESCRIPTION

Aspects of the disclosure are provided in the following description andrelated drawings directed to various examples provided for illustrationpurposes. Alternate aspects may be devised without departing from thescope of the disclosure. Additionally, well-known elements of thedisclosure will not be described in detail or will be omitted so as notto obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any aspect described hereinas “exemplary” and/or “example” is not necessarily to be construed aspreferred or advantageous over other aspects. Likewise, the term“aspects of the disclosure” does not require that all aspects of thedisclosure include the discussed feature, advantage or mode ofoperation.

Those of skill in the art will appreciate that the information andsignals described below may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the description below may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof, depending inpart on the particular application, in part on the desired design, inpart on the corresponding technology, etc.

Further, many aspects are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, the sequence(s)of actions described herein can be considered to be embodied entirelywithin any form of non-transitory computer-readable storage mediumhaving stored therein a corresponding set of computer instructions that,upon execution, would cause or instruct an associated processor of adevice to perform the functionality described herein. Thus, the variousaspects of the disclosure may be embodied in a number of differentforms, all of which have been contemplated to be within the scope of theclaimed subject matter. In addition, for each of the aspects describedherein, the corresponding form of any such aspects may be describedherein as, for example, “logic configured to” perform the describedaction.

As used herein, the terms “user equipment” (UE) and “base station” arenot intended to be specific or otherwise limited to any particular radioaccess technology (RAT), unless otherwise noted. In general, a UE may beany wireless communication device (e.g., a mobile phone, router, tabletcomputer, laptop computer, consumer asset locating device, wearable(e.g., smartwatch, glasses, augmented reality (AR)/virtual reality (VR)headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.),Internet of Things (IoT) device, etc.) used by a user to communicateover a wireless communications network. A UE may be mobile or may (e.g.,at certain times) be stationary, and may communicate with a radio accessnetwork (RAN). As used herein, the term “UE” may be referred tointerchangeably as an “access terminal” or “AT,” a “client device,” a“wireless device,” a “subscriber device,” a “subscriber terminal,” a“subscriber station,” a “user terminal” or “UT,” a “mobile device,” a“mobile terminal,” a “mobile station,” or variations thereof. Generally,UEs can communicate with a core network via a RAN, and through the corenetwork the UEs can be connected with external networks such as theInternet and with other UEs. Of course, other mechanisms of connectingto the core network and/or the Internet are also possible for the UEs,such as over wired access networks, wireless local area network (WLAN)networks (e.g., based on the Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 specification, etc.) and so on.

A base station may operate according to one of several RATs incommunication with UEs depending on the network in which it is deployed,and may be alternatively referred to as an access point (AP), a networknode, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), aNew Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A basestation may be used primarily to support wireless access by UEs,including supporting data, voice, and/or signaling connections for thesupported UEs. In some systems a base station may provide purely edgenode signaling functions while in other systems it may provideadditional control and/or network management functions. A communicationlink through which UEs can send signals to a base station is called anuplink (UL) channel (e.g., a reverse traffic channel, a reverse controlchannel, an access channel, etc.). A communication link through whichthe base station can send signals to UEs is called a downlink (DL) orforward link channel (e.g., a paging channel, a control channel, abroadcast channel, a forward traffic channel, etc.). As used herein theterm traffic channel (TCH) can refer to either an uplink/reverse ordownlink/forward traffic channel.

The term “base station” may refer to a single physicaltransmission-reception point (TRP) or to multiple physical TRPs that mayor may not be co-located. For example, where the term “base station”refers to a single physical TRP, the physical TRP may be an antenna ofthe base station corresponding to a cell (or several cell sectors) ofthe base station. Where the term “base station” refers to multipleco-located physical TRPs, the physical TRPs may be an array of antennas(e.g., as in a multiple-input multiple-output (MIMO) system or where thebase station employs beamforming) of the base station. Where the term“base station” refers to multiple non-co-located physical TRPs, thephysical TRPs may be a distributed antenna system (DAS) (a network ofspatially separated antennas connected to a common source via atransport medium) or a remote radio head (RRH) (a remote base stationconnected to a serving base station). Alternatively, the non-co-locatedphysical TRPs may be the serving base station receiving the measurementreport from the UE and a neighbor base station whose reference radiofrequency (RF) signals the UE is measuring. Because a TRP is the pointfrom which a base station transmits and receives wireless signals, asused herein, references to transmission from or reception at a basestation are to be understood as referring to a particular TRP of thebase station.

In some implementations that support positioning of UEs, a base stationmay not support wireless access by UEs (e.g., may not support data,voice, and/or signaling connections for UEs), but may instead transmitreference signals to UEs to be measured by the UEs, and/or may receiveand measure signals transmitted by the UEs. Such a base station may bereferred to as a positioning beacon (e.g., when transmitting signals toUEs) and/or as a location measurement unit (e.g., when receiving andmeasuring signals from UEs).

An “RF signal” comprises an electromagnetic wave of a given frequencythat transports information through the space between a transmitter anda receiver. As used herein, a transmitter may transmit a single “RFsignal” or multiple “RF signals” to a receiver. However, the receivermay receive multiple “RF signals” corresponding to each transmitted RFsignal due to the propagation characteristics of RF signals throughmultipath channels. The same transmitted RF signal on different pathsbetween the transmitter and receiver may be referred to as a “multipath”RF signal. As used herein, an RF signal may also be referred to as a“wireless signal” or simply a “signal” where it is clear from thecontext that the term “signal” refers to a wireless signal or an RFsignal.

FIG. 1 illustrates an example wireless communications system 100,according to aspects of the disclosure. The wireless communicationssystem 100 (which may also be referred to as a wireless wide areanetwork (WWAN)) may include various base stations 102 (labeled “BS”) andvarious UEs 104. The base stations 102 may include macro cell basestations (high power cellular base stations) and/or small cell basestations (low power cellular base stations). In an aspect, the macrocell base stations may include eNBs and/or ng-eNBs where the wirelesscommunications system 100 corresponds to an LTE network, or gNBs wherethe wireless communications system 100 corresponds to a NR network, or acombination of both, and the small cell base stations may includefemtocells, picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with acore network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC))through backhaul links 122, and through the core network 170 to one ormore location servers 172 (e.g., a location management function (LMF) ora secure user plane location (SUPL) location platform (SLP)). Thelocation server(s) 172 may be part of core network 170 or may beexternal to core network 170. In addition to other functions, the basestations 102 may perform functions that relate to one or more oftransferring user data, radio channel ciphering and deciphering,integrity protection, header compression, mobility control functions(e.g., handover, dual connectivity), inter-cell interferencecoordination, connection setup and release, load balancing, distributionfor non-access stratum (NAS) messages, NAS node selection,synchronization, RAN sharing, multimedia broadcast multicast service(MBMS), subscriber and equipment trace, RAN information management(RIM), paging, positioning, and delivery of warning messages. The basestations 102 may communicate with each other directly or indirectly(e.g., through the EPC/5GC) over backhaul links 134, which may be wiredor wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. In an aspect, one or more cellsmay be supported by a base station 102 in each geographic coverage area110. A “cell” is a logical communication entity used for communicationwith a base station (e.g., over some frequency resource, referred to asa carrier frequency, component carrier, carrier, band, or the like), andmay be associated with an identifier (e.g., a physical cell identifier(PCI), an enhanced cell identifier (ECI), a virtual cell identifier(VCI), a cell global identifier (CGI), etc.) for distinguishing cellsoperating via the same or a different carrier frequency. In some cases,different cells may be configured according to different protocol types(e.g., machine-type communication (MTC), narrowband IoT (NB-IoT),enhanced mobile broadband (eMBB), or others) that may provide access fordifferent types of UEs. Because a cell is supported by a specific basestation, the term “cell” may refer to either or both of the logicalcommunication entity and the base station that supports it, depending onthe context. In addition, because a TRP is typically the physicaltransmission point of a cell, the terms “cell” and “TRP” may be usedinterchangeably. In some cases, the term “cell” may also refer to ageographic coverage area of a base station (e.g., a sector), insofar asa carrier frequency can be detected and used for communication withinsome portion of geographic coverage areas 110.

While neighboring macro cell base station 102 geographic coverage areas110 may partially overlap (e.g., in a handover region), some of thegeographic coverage areas 110 may be substantially overlapped by alarger geographic coverage area 110. For example, a small cell basestation 102′ (labeled “SC” for “small cell”) may have a geographiccoverage area 110′ that substantially overlaps with the geographiccoverage area 110 of one or more macro cell base stations 102. A networkthat includes both small cell and macro cell base stations may be knownas a heterogeneous network. A heterogeneous network may also includehome eNBs (HeNBs), which may provide service to a restricted group knownas a closed subscriber group (CSG).

The communication links 120 between the base stations 102 and the UEs104 may include uplink (also referred to as reverse link) transmissionsfrom a UE 104 to a base station 102 and/or downlink (DL) (also referredto as forward link) transmissions from a base station 102 to a UE 104.The communication links 120 may use MIMO antenna technology, includingspatial multiplexing, beamforming, and/or transmit diversity. Thecommunication links 120 may be through one or more carrier frequencies.Allocation of carriers may be asymmetric with respect to downlink anduplink (e.g., more or less carriers may be allocated for downlink thanfor uplink).

The wireless communications system 100 may further include a wirelesslocal area network (WLAN) access point (AP) 150 in communication withWLAN stations (STAs) 152 via communication links 154 in an unlicensedfrequency spectrum (e.g., 5 GHz). When communicating in an unlicensedfrequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may performa clear channel assessment (CCA) or listen before talk (LBT) procedureprior to communicating in order to determine whether the channel isavailable.

The small cell base station 102′ may operate in a licensed and/or anunlicensed frequency spectrum. When operating in an unlicensed frequencyspectrum, the small cell base station 102′ may employ LTE or NRtechnology and use the same 5 GHz unlicensed frequency spectrum as usedby the WLAN AP 150. The small cell base station 102′, employing LTE/5Gin an unlicensed frequency spectrum, may boost coverage to and/orincrease capacity of the access network. NR in unlicensed spectrum maybe referred to as NR-U. LTE in an unlicensed spectrum may be referred toas LTE-U, licensed assisted access (LAA), or MulteFire.

The wireless communications system 100 may further include a millimeterwave (mmW) base station 180 that may operate in mmW frequencies and/ornear mmW frequencies in communication with a UE 182. Extremely highfrequency (EHF) is part of the RF in the electromagnetic spectrum. EHFhas a range of 30 GHz to 300 GHz and a wavelength between 1 millimeterand 10 millimeters. Radio waves in this band may be referred to as amillimeter wave. Near mmW may extend down to a frequency of 3 GHz with awavelength of 100 millimeters. The super high frequency (SHF) bandextends between 3 GHz and 30 GHz, also referred to as centimeter wave.Communications using the mmW/near mmW radio frequency band have highpath loss and a relatively short range. The mmW base station 180 and theUE 182 may utilize beamforming (transmit and/or receive) over a mmWcommunication link 184 to compensate for the extremely high path lossand short range. Further, it will be appreciated that in alternativeconfigurations, one or more base stations 102 may also transmit usingmmW or near mmW and beamforming. Accordingly, it will be appreciatedthat the foregoing illustrations are merely examples and should not beconstrued to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in aspecific direction. Traditionally, when a network node (e.g., a basestation) broadcasts an RF signal, it broadcasts the signal in alldirections (omni-directionally). With transmit beamforming, the networknode determines where a given target device (e.g., a UE) is located(relative to the transmitting network node) and projects a strongerdownlink RF signal in that specific direction, thereby providing afaster (in terms of data rate) and stronger RF signal for the receivingdevice(s). To change the directionality of the RF signal whentransmitting, a network node can control the phase and relativeamplitude of the RF signal at each of the one or more transmitters thatare broadcasting the RF signal. For example, a network node may use anarray of antennas (referred to as a “phased array” or an “antennaarray”) that creates a beam of RF waves that can be “steered” to pointin different directions, without actually moving the antennas.Specifically, the RF current from the transmitter is fed to theindividual antennas with the correct phase relationship so that theradio waves from the separate antennas add together to increase theradiation in a desired direction, while cancelling to suppress radiationin undesired directions.

Transmit beams may be quasi-co-located, meaning that they appear to thereceiver (e.g., a UE) as having the same parameters, regardless ofwhether or not the transmitting antennas of the network node themselvesare physically co-located. In NR, there are four types ofquasi-co-location (QCL) relations. Specifically, a QCL relation of agiven type means that certain parameters about a second reference RFsignal on a second beam can be derived from information about a sourcereference RF signal on a source beam. Thus, if the source reference RFsignal is QCL Type A, the receiver can use the source reference RFsignal to estimate the Doppler shift, Doppler spread, average delay, anddelay spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type B, the receivercan use the source reference RF signal to estimate the Doppler shift andDoppler spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type C, the receivercan use the source reference RF signal to estimate the Doppler shift andaverage delay of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type D, the receivercan use the source reference RF signal to estimate the spatial receiveparameter of a second reference RF signal transmitted on the samechannel.

In receive beamforming, the receiver uses a receive beam to amplify RFsignals detected on a given channel. For example, the receiver canincrease the gain setting and/or adjust the phase setting of an array ofantennas in a particular direction to amplify (e.g., to increase thegain level of) the RF signals received from that direction. Thus, when areceiver is said to beamform in a certain direction, it means the beamgain in that direction is high relative to the beam gain along otherdirections, or the beam gain in that direction is the highest comparedto the beam gain in that direction of all other receive beams availableto the receiver. This results in a stronger received signal strength(e.g., reference signal received power (RSRP), reference signal receivedquality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) ofthe RF signals received from that direction.

Transmit and receive beams may be spatially related. A spatial relationmeans that parameters for a second beam (e.g., a transmit or receivebeam) for a second reference signal can be derived from informationabout a first beam (e.g., a receive beam or a transmit beam) for a firstreference signal. For example, a UE may use a particular receive beam toreceive a reference downlink reference signal (e.g., synchronizationsignal block (SSB)) from a base station. The UE can then form a transmitbeam for sending an uplink reference signal (e.g., sounding referencesignal (SRS)) to that base station based on the parameters of thereceive beam.

Note that a “downlink” beam may be either a transmit beam or a receivebeam, depending on the entity forming it. For example, if a base stationis forming the downlink beam to transmit a reference signal to a UE, thedownlink beam is a transmit beam. If the UE is forming the downlinkbeam, however, it is a receive beam to receive the downlink referencesignal. Similarly, an “uplink” beam may be either a transmit beam or areceive beam, depending on the entity forming it. For example, if a basestation is forming the uplink beam, it is an uplink receive beam, and ifa UE is forming the uplink beam, it is an uplink transmit beam.

In 5G, the frequency spectrum in which wireless nodes (e.g., basestations 102/180, UEs 104/182) operate is divided into multiplefrequency ranges, FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). mmWfrequency bands generally include the FR2, FR3, and FR4 frequencyranges. As such, the terms “mmW” and “FR2” or “FR3” or “FR4” maygenerally be used interchangeably.

In a multi-carrier system, such as 5G, one of the carrier frequencies isreferred to as the “primary carrier” or “anchor carrier” or “primaryserving cell” or “PCell,” and the remaining carrier frequencies arereferred to as “secondary carriers” or “secondary serving cells” or“SCells.” In carrier aggregation, the anchor carrier is the carrieroperating on the primary frequency (e.g., FR1) utilized by a UE 104/182and the cell in which the UE 104/182 either performs the initial radioresource control (RRC) connection establishment procedure or initiatesthe RRC connection re-establishment procedure. The primary carriercarries all common and UE-specific control channels, and may be acarrier in a licensed frequency (however, this is not always the case).A secondary carrier is a carrier operating on a second frequency (e.g.,FR2) that may be configured once the RRC connection is establishedbetween the UE 104 and the anchor carrier and that may be used toprovide additional radio resources. In some cases, the secondary carriermay be a carrier in an unlicensed frequency. The secondary carrier maycontain only necessary signaling information and signals, for example,those that are UE-specific may not be present in the secondary carrier,since both primary uplink and downlink carriers are typicallyUE-specific. This means that different UEs 104/182 in a cell may havedifferent downlink primary carriers. The same is true for the uplinkprimary carriers. The network is able to change the primary carrier ofany UE 104/182 at any time. This is done, for example, to balance theload on different carriers. Because a “serving cell” (whether a PCell oran SCell) corresponds to a carrier frequency/component carrier overwhich some base station is communicating, the term “cell,” “servingcell,” “component carrier,” “carrier frequency,” and the like can beused interchangeably.

For example, still referring to FIG. 1 , one of the frequencies utilizedby the macro cell base stations 102 may be an anchor carrier (or“PCell”) and other frequencies utilized by the macro cell base stations102 and/or the mmW base station 180 may be secondary carriers(“SCells”). The simultaneous transmission and/or reception of multiplecarriers enables the UE 104/182 to significantly increase its datatransmission and/or reception rates. For example, two 20 MHz aggregatedcarriers in a multi-carrier system would theoretically lead to atwo-fold increase in data rate (i.e., 40 MHz), compared to that attainedby a single 20 MHz carrier.

The wireless communications system 100 may further include a UE 164 thatmay communicate with a macro cell base station 102 over a communicationlink 120 and/or the mmW base station 180 over a mmW communication link184. For example, the macro cell base station 102 may support a PCelland one or more SCells for the UE 164 and the mmW base station 180 maysupport one or more SCells for the UE 164.

In the example of FIG. 1 , any of the illustrated UEs (shown in FIG. 1as a single UE 104 for simplicity) may receive signals 124 from one ormore Earth orbiting space vehicles (SVs) 112 (e.g., satellites). In anaspect, the SVs 112 may be part of a satellite positioning system that aUE 104 can use as an independent source of location information. Asatellite positioning system typically includes a system of transmitters(e.g., SVs 112) positioned to enable receivers (e.g., UEs 104) todetermine their location on or above the Earth based, at least in part,on positioning signals (e.g., signals 124) received from thetransmitters. Such a transmitter typically transmits a signal markedwith a repeating pseudo-random noise (PN) code of a set number of chips.While typically located in SVs 112, transmitters may sometimes belocated on ground-based control stations, base stations 102, and/orother UEs 104. A UE 104 may include one or more dedicated receiversspecifically designed to receive signals 124 for deriving geo locationinformation from the SVs 112.

In a satellite positioning system, the use of signals 124 can beaugmented by various satellite-based augmentation systems (SBAS) thatmay be associated with or otherwise enabled for use with one or moreglobal and/or regional navigation satellite systems. For example an SBASmay include an augmentation system(s) that provides integrityinformation, differential corrections, etc., such as the Wide AreaAugmentation System (WAAS), the European Geostationary NavigationOverlay Service (EGNOS), the Multi-functional Satellite AugmentationSystem (MSAS), the Global Positioning System (GPS) Aided Geo AugmentedNavigation or GPS and Geo Augmented Navigation system (GAGAN), and/orthe like. Thus, as used herein, a satellite positioning system mayinclude any combination of one or more global and/or regional navigationsatellites associated with such one or more satellite positioningsystems.

In an aspect, SVs 112 may additionally or alternatively be part of oneor more non-terrestrial networks (NTNs). In an NTN, an SV 112 isconnected to an earth station (also referred to as a ground station, NTNgateway, or gateway), which in turn is connected to an element in a 5Gnetwork, such as a modified base station 102 (without a terrestrialantenna) or a network node in a 5GC. This element would in turn provideaccess to other elements in the 5G network and ultimately to entitiesexternal to the 5G network, such as Internet web servers and other userdevices. In that way, a UE 104 may receive communication signals (e.g.,signals 124) from an SV 112 instead of, or in addition to, communicationsignals from a terrestrial base station 102.

The wireless communications system 100 may further include one or moreUEs, such as UE 190, that connects indirectly to one or morecommunication networks via one or more device-to-device (D2D)peer-to-peer (P2P) links (referred to as “sidelinks”). In the example ofFIG. 1 , UE 190 has a D2D P2P link 192 with one of the UEs 104 connectedto one of the base stations 102 (e.g., through which UE 190 mayindirectly obtain cellular connectivity) and a D2D P2P link 194 withWLAN STA 152 connected to the WLAN AP 150 (through which UE 190 mayindirectly obtain WLAN-based Internet connectivity). In an example, theD2D P2P links 192 and 194 may be supported with any well-known D2D RAT,such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, and so on.

FIG. 2A illustrates an example wireless network structure 200. Forexample, a 5GC 210 (also referred to as a Next Generation Core (NGC))can be viewed functionally as control plane (C-plane) functions 214(e.g., UE registration, authentication, network access, gatewayselection, etc.) and user plane (U-plane) functions 212, (e.g., UEgateway function, access to data networks, IP routing, etc.) whichoperate cooperatively to form the core network. User plane interface(NG-U) 213 and control plane interface (NG-C) 215 connect the gNB 222 tothe 5GC 210 and specifically to the user plane functions 212 and controlplane functions 214, respectively. In an additional configuration, anng-eNB 224 may also be connected to the 5GC 210 via NG-C 215 to thecontrol plane functions 214 and NG-U 213 to user plane functions 212.Further, ng-eNB 224 may directly communicate with gNB 222 via a backhaulconnection 223. In some configurations, a Next Generation RAN (NG-RAN)220 may have one or more gNBs 222, while other configurations includeone or more of both ng-eNBs 224 and gNBs 222. Either (or both) gNB 222or ng-eNB 224 may communicate with one or more UEs 204 (e.g., any of theUEs described herein).

Another optional aspect may include a location server 230, which may bein communication with the 5GC 210 to provide location assistance forUE(s) 204. The location server 230 can be implemented as a plurality ofseparate servers (e.g., physically separate servers, different softwaremodules on a single server, different software modules spread acrossmultiple physical servers, etc.), or alternately may each correspond toa single server. The location server 230 can be configured to supportone or more location services for UEs 204 that can connect to thelocation server 230 via the core network, 5GC 210, and/or via theInternet (not illustrated). Further, the location server 230 may beintegrated into a component of the core network, or alternatively may beexternal to the core network (e.g., a third party server, such as anoriginal equipment manufacturer (OEM) server or service server).

FIG. 2B illustrates another example wireless network structure 250. A5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be viewedfunctionally as control plane functions, provided by an access andmobility management function (AMF) 264, and user plane functions,provided by a user plane function (UPF) 262, which operate cooperativelyto form the core network (i.e., 5GC 260). The functions of the AMF 264include registration management, connection management, reachabilitymanagement, mobility management, lawful interception, transport forsession management (SM) messages between one or more UEs 204 (e.g., anyof the UEs described herein) and a session management function (SMF)266, transparent proxy services for routing SM messages, accessauthentication and access authorization, transport for short messageservice (SMS) messages between the UE 204 and the short message servicefunction (SMSF) (not shown), and security anchor functionality (SEAF).The AMF 264 also interacts with an authentication server function (AUSF)(not shown) and the UE 204, and receives the intermediate key that wasestablished as a result of the UE 204 authentication process. In thecase of authentication based on a UMTS (universal mobiletelecommunications system) subscriber identity module (USIM), the AMF264 retrieves the security material from the AUSF. The functions of theAMF 264 also include security context management (SCM). The SCM receivesa key from the SEAF that it uses to derive access-network specific keys.The functionality of the AMF 264 also includes location servicesmanagement for regulatory services, transport for location servicesmessages between the UE 204 and a location management function (LMF) 270(which acts as a location server 230), transport for location servicesmessages between the NG-RAN 220 and the LMF 270, evolved packet system(EPS) bearer identifier allocation for interworking with the EPS, and UE204 mobility event notification. In addition, the AMF 264 also supportsfunctionalities for non-3GPP (Third Generation Partnership Project)access networks.

Functions of the UPF 262 include acting as an anchor point forintra-/inter-RAT mobility (when applicable), acting as an externalprotocol data unit (PDU) session point of interconnect to a data network(not shown), providing packet routing and forwarding, packet inspection,user plane policy rule enforcement (e.g., gating, redirection, trafficsteering), lawful interception (user plane collection), traffic usagereporting, quality of service (QoS) handling for the user plane (e.g.,uplink/downlink rate enforcement, reflective QoS marking in thedownlink), uplink traffic verification (service data flow (SDF) to QoSflow mapping), transport level packet marking in the uplink anddownlink, downlink packet buffering and downlink data notificationtriggering, and sending and forwarding of one or more “end markers” tothe source RAN node. The UPF 262 may also support transfer of locationservices messages over a user plane between the UE 204 and a locationserver, such as an SLP 272.

The functions of the SMF 266 include session management, UE Internetprotocol (IP) address allocation and management, selection and controlof user plane functions, configuration of traffic steering at the UPF262 to route traffic to the proper destination, control of part ofpolicy enforcement and QoS, and downlink data notification. Theinterface over which the SMF 266 communicates with the AMF 264 isreferred to as the N11 interface.

Another optional aspect may include an LMF 270, which may be incommunication with the 5GC 260 to provide location assistance for UEs204. The LMF 270 can be implemented as a plurality of separate servers(e.g., physically separate servers, different software modules on asingle server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The LMF 270 can be configured to support one or more locationservices for UEs 204 that can connect to the LMF 270 via the corenetwork, 5GC 260, and/or via the Internet (not illustrated). The SLP 272may support similar functions to the LMF 270, but whereas the LMF 270may communicate with the AMF 264, NG-RAN 220, and UEs 204 over a controlplane (e.g., using interfaces and protocols intended to convey signalingmessages and not voice or data), the SLP 272 may communicate with UEs204 and external clients (not shown in FIG. 2B) over a user plane (e.g.,using protocols intended to carry voice and/or data like thetransmission control protocol (TCP) and/or IP).

User plane interface 263 and control plane interface 265 connect the 5GC260, and specifically the UPF 262 and AMF 264, respectively, to one ormore gNBs 222 and/or ng-eNBs 224 in the NG-RAN 220. The interfacebetween gNB(s) 222 and/or ng-eNB(s) 224 and the AMF 264 is referred toas the “N2” interface, and the interface between gNB(s) 222 and/orng-eNB(s) 224 and the UPF 262 is referred to as the “N3” interface. ThegNB(s) 222 and/or ng-eNB(s) 224 of the NG-RAN 220 may communicatedirectly with each other via backhaul connections 223, referred to asthe “Xn-C” interface. One or more of gNBs 222 and/or ng-eNBs 224 maycommunicate with one or more UEs 204 over a wireless interface, referredto as the “Uu” interface.

The functionality of a gNB 222 is divided between a gNB central unit(gNB-CU) 226 and one or more gNB distributed units (gNB-DUs) 228. Theinterface 232 between the gNB-CU 226 and the one or more gNB-DUs 228 isreferred to as the “F1” interface. A gNB-CU 226 is a logical node thatincludes the base station functions of transferring user data, mobilitycontrol, radio access network sharing, positioning, session management,and the like, except for those functions allocated exclusively to thegNB-DU(s) 228. More specifically, the gNB-CU 226 hosts the radioresource control (RRC), service data adaptation protocol (SDAP), andpacket data convergence protocol (PDCP) protocols of the gNB 222. AgNB-DU 228 is a logical node that hosts the radio link control (RLC),medium access control (MAC), and physical (PHY) layers of the gNB 222.Its operation is controlled by the gNB-CU 226. One gNB-DU 228 cansupport one or more cells, and one cell is supported by only one gNB-DU228. Thus, a UE 204 communicates with the gNB-CU 226 via the RRC, SDAP,and PDCP layers and with a gNB-DU 228 via the RLC, MAC, and PHY layers.

FIGS. 3A, 3B, and 3C illustrate several example components (representedby corresponding blocks) that may be incorporated into a UE 302 (whichmay correspond to any of the UEs described herein), a base station 304(which may correspond to any of the base stations described herein), anda network entity 306 (which may correspond to or embody any of thenetwork functions described herein, including the location server 230and the LMF 270, or alternatively may be independent from the NG-RAN 220and/or 5GC 210/260 infrastructure depicted in FIGS. 2A and 2B, such as aprivate network) to support the file transmission operations as taughtherein. It will be appreciated that these components may be implementedin different types of apparatuses in different implementations (e.g., inan ASIC, in a system-on-chip (SoC), etc.). The illustrated componentsmay also be incorporated into other apparatuses in a communicationsystem. For example, other apparatuses in a system may includecomponents similar to those described to provide similar functionality.Also, a given apparatus may contain one or more of the components. Forexample, an apparatus may include multiple transceiver components thatenable the apparatus to operate on multiple carriers and/or communicatevia different technologies.

The UE 302 and the base station 304 each include one or more wirelesswide area network (WWAN) transceivers 310 and 350, respectively,providing means for communicating (e.g., means for transmitting, meansfor receiving, means for measuring, means for tuning, means forrefraining from transmitting, etc.) via one or more wirelesscommunication networks (not shown), such as an NR network, an LTEnetwork, a GSM network, and/or the like. The WWAN transceivers 310 and350 may each be connected to one or more antennas 316 and 356,respectively, for communicating with other network nodes, such as otherUEs, access points, base stations (e.g., eNBs, gNBs), etc., via at leastone designated RAT (e.g., NR, LTE, GSM, etc.) over a wirelesscommunication medium of interest (e.g., some set of time/frequencyresources in a particular frequency spectrum). The WWAN transceivers 310and 350 may be variously configured for transmitting and encodingsignals 318 and 358 (e.g., messages, indications, information, and soon), respectively, and, conversely, for receiving and decoding signals318 and 358 (e.g., messages, indications, information, pilots, and soon), respectively, in accordance with the designated RAT. Specifically,the WWAN transceivers 310 and 350 include one or more transmitters 314and 354, respectively, for transmitting and encoding signals 318 and358, respectively, and one or more receivers 312 and 352, respectively,for receiving and decoding signals 318 and 358, respectively.

The UE 302 and the base station 304 each also include, at least in somecases, one or more short-range wireless transceivers 320 and 360,respectively. The short-range wireless transceivers 320 and 360 may beconnected to one or more antennas 326 and 366, respectively, and providemeans for communicating (e.g., means for transmitting, means forreceiving, means for measuring, means for tuning, means for refrainingfrom transmitting, etc.) with other network nodes, such as other UEs,access points, base stations, etc., via at least one designated RAT(e.g., WiFi, LTE-D, Bluetooth®, Zigbee®, Z-Wave®, PC5, dedicatedshort-range communications (DSRC), wireless access for vehicularenvironments (WAVE), near-field communication (NFC), etc.) over awireless communication medium of interest. The short-range wirelesstransceivers 320 and 360 may be variously configured for transmittingand encoding signals 328 and 368 (e.g., messages, indications,information, and so on), respectively, and, conversely, for receivingand decoding signals 328 and 368 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the short-range wireless transceivers 320and 360 include one or more transmitters 324 and 364, respectively, fortransmitting and encoding signals 328 and 368, respectively, and one ormore receivers 322 and 362, respectively, for receiving and decodingsignals 328 and 368, respectively. As specific examples, the short-rangewireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth®transceivers, Zigbee® and/or Z-Wave® transceivers, NFC transceivers, orvehicle-to-vehicle (V2V) and/or vehicle-to-everything (V2X)transceivers.

The UE 302 and the base station 304 also include, at least in somecases, satellite signal receivers 330 and 370. The satellite signalreceivers 330 and 370 may be connected to one or more antennas 336 and376, respectively, and may provide means for receiving and/or measuringsatellite positioning/communication signals 338 and 378, respectively.Where the satellite signal receivers 330 and 370 are satellitepositioning system receivers, the satellite positioning/communicationsignals 338 and 378 may be global positioning system (GPS) signals,global navigation satellite system (GLONASS) signals, Galileo signals,Beidou signals, Indian Regional Navigation Satellite System (NAVIC),Quasi-Zenith Satellite System (QZSS), etc. Where the satellite signalreceivers 330 and 370 are non-terrestrial network (NTN) receivers, thesatellite positioning/communication signals 338 and 378 may becommunication signals (e.g., carrying control and/or user data)originating from a 5G network. The satellite signal receivers 330 and370 may comprise any suitable hardware and/or software for receiving andprocessing satellite positioning/communication signals 338 and 378,respectively. The satellite signal receivers 330 and 370 may requestinformation and operations as appropriate from the other systems, and,at least in some cases, perform calculations to determine locations ofthe UE 302 and the base station 304, respectively, using measurementsobtained by any suitable satellite positioning system algorithm.

The base station 304 and the network entity 306 each include one or morenetwork transceivers 380 and 390, respectively, providing means forcommunicating (e.g., means for transmitting, means for receiving, etc.)with other network entities (e.g., other base stations 304, othernetwork entities 306). For example, the base station 304 may employ theone or more network transceivers 380 to communicate with other basestations 304 or network entities 306 over one or more wired or wirelessbackhaul links. As another example, the network entity 306 may employthe one or more network transceivers 390 to communicate with one or morebase station 304 over one or more wired or wireless backhaul links, orwith other network entities 306 over one or more wired or wireless corenetwork interfaces.

A transceiver may be configured to communicate over a wired or wirelesslink. A transceiver (whether a wired transceiver or a wirelesstransceiver) includes transmitter circuitry (e.g., transmitters 314,324, 354, 364) and receiver circuitry (e.g., receivers 312, 322, 352,362). A transceiver may be an integrated device (e.g., embodyingtransmitter circuitry and receiver circuitry in a single device) in someimplementations, may comprise separate transmitter circuitry andseparate receiver circuitry in some implementations, or may be embodiedin other ways in other implementations. The transmitter circuitry andreceiver circuitry of a wired transceiver (e.g., network transceivers380 and 390 in some implementations) may be coupled to one or more wirednetwork interface ports. Wireless transmitter circuitry (e.g.,transmitters 314, 324, 354, 364) may include or be coupled to aplurality of antennas (e.g., antennas 316, 326, 356, 366), such as anantenna array, that permits the respective apparatus (e.g., UE 302, basestation 304) to perform transmit “beamforming,” as described herein.Similarly, wireless receiver circuitry (e.g., receivers 312, 322, 352,362) may include or be coupled to a plurality of antennas (e.g.,antennas 316, 326, 356, 366), such as an antenna array, that permits therespective apparatus (e.g., UE 302, base station 304) to perform receivebeamforming, as described herein. In an aspect, the transmittercircuitry and receiver circuitry may share the same plurality ofantennas (e.g., antennas 316, 326, 356, 366), such that the respectiveapparatus can only receive or transmit at a given time, not both at thesame time. A wireless transceiver (e.g., WWAN transceivers 310 and 350,short-range wireless transceivers 320 and 360) may also include anetwork listen module (NLM) or the like for performing variousmeasurements.

As used herein, the various wireless transceivers (e.g., transceivers310, 320, 350, and 360, and network transceivers 380 and 390 in someimplementations) and wired transceivers (e.g., network transceivers 380and 390 in some implementations) may generally be characterized as “atransceiver,” “at least one transceiver,” or “one or more transceivers.”As such, whether a particular transceiver is a wired or wirelesstransceiver may be inferred from the type of communication performed.For example, backhaul communication between network devices or serverswill generally relate to signaling via a wired transceiver, whereaswireless communication between a UE (e.g., UE 302) and a base station(e.g., base station 304) will generally relate to signaling via awireless transceiver.

The UE 302, the base station 304, and the network entity 306 alsoinclude other components that may be used in conjunction with theoperations as disclosed herein. The UE 302, the base station 304, andthe network entity 306 include one or more processors 332, 384, and 394,respectively, for providing functionality relating to, for example,wireless communication, and for providing other processingfunctionality. The processors 332, 384, and 394 may therefore providemeans for processing, such as means for determining, means forcalculating, means for receiving, means for transmitting, means forindicating, etc. In an aspect, the processors 332, 384, and 394 mayinclude, for example, one or more general purpose processors, multi-coreprocessors, central processing units (CPUs), ASICs, digital signalprocessors (DSPs), field programmable gate arrays (FPGAs), otherprogrammable logic devices or processing circuitry, or variouscombinations thereof.

The UE 302, the base station 304, and the network entity 306 includememory circuitry implementing memories 340, 386, and 396 (e.g., eachincluding a memory device), respectively, for maintaining information(e.g., information indicative of reserved resources, thresholds,parameters, and so on). The memories 340, 386, and 396 may thereforeprovide means for storing, means for retrieving, means for maintaining,etc. In some cases, the UE 302, the base station 304, and the networkentity 306 may include positioning component 342, 388, and 398,respectively. The positioning component 342, 388, and 398 may behardware circuits that are part of or coupled to the processors 332,384, and 394, respectively, that, when executed, cause the UE 302, thebase station 304, and the network entity 306 to perform thefunctionality described herein. In other aspects, the positioningcomponent 342, 388, and 398 may be external to the processors 332, 384,and 394 (e.g., part of a modem processing system, integrated withanother processing system, etc.). Alternatively, the positioningcomponent 342, 388, and 398 may be memory modules stored in the memories340, 386, and 396, respectively, that, when executed by the processors332, 384, and 394 (or a modem processing system, another processingsystem, etc.), cause the UE 302, the base station 304, and the networkentity 306 to perform the functionality described herein. FIG. 3Aillustrates possible locations of the positioning component 342, whichmay be, for example, part of the one or more WWAN transceivers 310, thememory 340, the one or more processors 332, or any combination thereof,or may be a standalone component. FIG. 3B illustrates possible locationsof the positioning component 388, which may be, for example, part of theone or more WWAN transceivers 350, the memory 386, the one or moreprocessors 384, or any combination thereof, or may be a standalonecomponent. FIG. 3C illustrates possible locations of the positioningcomponent 398, which may be, for example, part of the one or morenetwork transceivers 390, the memory 396, the one or more processors394, or any combination thereof, or may be a standalone component.

The UE 302 may include one or more sensors 344 coupled to the one ormore processors 332 to provide means for sensing or detecting movementand/or orientation information that is independent of motion dataderived from signals received by the one or more WWAN transceivers 310,the one or more short-range wireless transceivers 320, and/or thesatellite signal receiver 330. By way of example, the sensor(s) 344 mayinclude an accelerometer (e.g., a micro-electrical mechanical systems(MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), analtimeter (e.g., a barometric pressure altimeter), and/or any other typeof movement detection sensor. Moreover, the sensor(s) 344 may include aplurality of different types of devices and combine their outputs inorder to provide motion information. For example, the sensor(s) 344 mayuse a combination of a multi-axis accelerometer and orientation sensorsto provide the ability to compute positions in two-dimensional (2D)and/or three-dimensional (3D) coordinate systems.

In addition, the UE 302 includes a user interface 346 providing meansfor providing indications (e.g., audible and/or visual indications) to auser and/or for receiving user input (e.g., upon user actuation of asensing device such a keypad, a touch screen, a microphone, and so on).Although not shown, the base station 304 and the network entity 306 mayalso include user interfaces.

Referring to the one or more processors 384 in more detail, in thedownlink, IP packets from the network entity 306 may be provided to theprocessor 384. The one or more processors 384 may implementfunctionality for an RRC layer, a packet data convergence protocol(PDCP) layer, a radio link control (RLC) layer, and a medium accesscontrol (MAC) layer. The one or more processors 384 may provide RRClayer functionality associated with broadcasting of system information(e.g., master information block (MIB), system information blocks (SIBs)), RRC connection control (e.g., RRC connection paging, RRC connectionestablishment, RRC connection modification, and RRC connection release),inter-RAT mobility, and measurement configuration for UE measurementreporting; PDCP layer functionality associated with headercompression/decompression, security (ciphering, deciphering, integrityprotection, integrity verification), and handover support functions; RLClayer functionality associated with the transfer of upper layer PDUs,error correction through automatic repeat request (ARQ), concatenation,segmentation, and reassembly of RLC service data units (SDUs),re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; andMAC layer functionality associated with mapping between logical channelsand transport channels, scheduling information reporting, errorcorrection, priority handling, and logical channel prioritization.

The transmitter 354 and the receiver 352 may implement Layer-1 (L1)functionality associated with various signal processing functions.Layer-1, which includes a physical (PHY) layer, may include errordetection on the transport channels, forward error correction (FEC)coding/decoding of the transport channels, interleaving, rate matching,mapping onto physical channels, modulation/demodulation of physicalchannels, and MIMO antenna processing. The transmitter 354 handlesmapping to signal constellations based on various modulation schemes(e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an orthogonalfrequency division multiplexing (OFDM) subcarrier, multiplexed with areference signal (e.g., pilot) in the time and/or frequency domain, andthen combined together using an inverse fast Fourier transform (IFFT) toproduce a physical channel carrying a time domain OFDM symbol stream.The OFDM symbol stream is spatially precoded to produce multiple spatialstreams. Channel estimates from a channel estimator may be used todetermine the coding and modulation scheme, as well as for spatialprocessing. The channel estimate may be derived from a reference signaland/or channel condition feedback transmitted by the UE 302. Eachspatial stream may then be provided to one or more different antennas356. The transmitter 354 may modulate an RF carrier with a respectivespatial stream for transmission.

At the UE 302, the receiver 312 receives a signal through its respectiveantenna(s) 316. The receiver 312 recovers information modulated onto anRF carrier and provides the information to the one or more processors332. The transmitter 314 and the receiver 312 implement Layer-1functionality associated with various signal processing functions. Thereceiver 312 may perform spatial processing on the information torecover any spatial streams destined for the UE 302. If multiple spatialstreams are destined for the UE 302, they may be combined by thereceiver 312 into a single OFDM symbol stream. The receiver 312 thenconverts the OFDM symbol stream from the time-domain to the frequencydomain using a fast Fourier transform (FFT). The frequency domain signalcomprises a separate OFDM symbol stream for each subcarrier of the OFDMsignal. The symbols on each subcarrier, and the reference signal, arerecovered and demodulated by determining the most likely signalconstellation points transmitted by the base station 304. These softdecisions may be based on channel estimates computed by a channelestimator. The soft decisions are then decoded and de-interleaved torecover the data and control signals that were originally transmitted bythe base station 304 on the physical channel. The data and controlsignals are then provided to the one or more processors 332, whichimplements Layer-3 (L3) and Layer-2 (L2) functionality.

In the uplink, the one or more processors 332 provides demultiplexingbetween transport and logical channels, packet reassembly, deciphering,header decompression, and control signal processing to recover IPpackets from the core network. The one or more processors 332 are alsoresponsible for error detection.

Similar to the functionality described in connection with the downlinktransmission by the base station 304, the one or more processors 332provides RRC layer functionality associated with system information(e.g., MIB, SIBs) acquisition, RRC connections, and measurementreporting; PDCP layer functionality associated with headercompression/decompression, and security (ciphering, deciphering,integrity protection, integrity verification); RLC layer functionalityassociated with the transfer of upper layer PDUs, error correctionthrough ARQ, concatenation, segmentation, and reassembly of RLC SDUs,re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; andMAC layer functionality associated with mapping between logical channelsand transport channels, multiplexing of MAC SDUs onto transport blocks(TBs), demultiplexing of MAC SDUs from TBs, scheduling informationreporting, error correction through hybrid automatic repeat request(HARD), priority handling, and logical channel prioritization.

Channel estimates derived by the channel estimator from a referencesignal or feedback transmitted by the base station 304 may be used bythe transmitter 314 to select the appropriate coding and modulationschemes, and to facilitate spatial processing. The spatial streamsgenerated by the transmitter 314 may be provided to different antenna(s)316. The transmitter 314 may modulate an RF carrier with a respectivespatial stream for transmission.

The uplink transmission is processed at the base station 304 in a mannersimilar to that described in connection with the receiver function atthe UE 302. The receiver 352 receives a signal through its respectiveantenna(s) 356. The receiver 352 recovers information modulated onto anRF carrier and provides the information to the one or more processors384.

In the uplink, the one or more processors 384 provides demultiplexingbetween transport and logical channels, packet reassembly, deciphering,header decompression, control signal processing to recover IP packetsfrom the UE 302. IP packets from the one or more processors 384 may beprovided to the core network. The one or more processors 384 are alsoresponsible for error detection.

For convenience, the UE 302, the base station 304, and/or the networkentity 306 are shown in FIGS. 3A, 3B, and 3C as including variouscomponents that may be configured according to the various examplesdescribed herein. It will be appreciated, however, that the illustratedcomponents may have different functionality in different designs. Inparticular, various components in FIGS. 3A to 3C are optional inalternative configurations and the various aspects includeconfigurations that may vary due to design choice, costs, use of thedevice, or other considerations. For example, in case of FIG. 3A, aparticular implementation of UE 302 may omit the WWAN transceiver(s) 310(e.g., a wearable device or tablet computer or PC or laptop may haveWi-Fi and/or Bluetooth capability without cellular capability), or mayomit the short-range wireless transceiver(s) 320 (e.g., cellular-only,etc.), or may omit the satellite signal receiver 330, or may omit thesensor(s) 344, and so on. In another example, in case of FIG. 3B, aparticular implementation of the base station 304 may omit the WWANtransceiver(s) 350 (e.g., a Wi-Fi “hotspot” access point withoutcellular capability), or may omit the short-range wirelesstransceiver(s) 360 (e.g., cellular-only, etc.), or may omit thesatellite receiver 370, and so on. For brevity, illustration of thevarious alternative configurations is not provided herein, but would bereadily understandable to one skilled in the art.

The various components of the UE 302, the base station 304, and thenetwork entity 306 may be communicatively coupled to each other overdata buses 334, 382, and 392, respectively. In an aspect, the data buses334, 382, and 392 may form, or be part of, a communication interface ofthe UE 302, the base station 304, and the network entity 306,respectively. For example, where different logical entities are embodiedin the same device (e.g., gNB and location server functionalityincorporated into the same base station 304), the data buses 334, 382,and 392 may provide communication between them.

The components of FIGS. 3A, 3B, and 3C may be implemented in variousways. In some implementations, the components of FIGS. 3A, 3B, and 3Cmay be implemented in one or more circuits such as, for example, one ormore processors and/or one or more ASICs (which may include one or moreprocessors). Here, each circuit may use and/or incorporate at least onememory component for storing information or executable code used by thecircuit to provide this functionality. For example, some or all of thefunctionality represented by blocks 310 to 346 may be implemented byprocessor and memory component(s) of the UE 302 (e.g., by execution ofappropriate code and/or by appropriate configuration of processorcomponents). Similarly, some or all of the functionality represented byblocks 350 to 388 may be implemented by processor and memorycomponent(s) of the base station 304 (e.g., by execution of appropriatecode and/or by appropriate configuration of processor components). Also,some or all of the functionality represented by blocks 390 to 398 may beimplemented by processor and memory component(s) of the network entity306 (e.g., by execution of appropriate code and/or by appropriateconfiguration of processor components). For simplicity, variousoperations, acts, and/or functions are described herein as beingperformed “by a UE,” “by a base station,” “by a network entity,” etc.However, as will be appreciated, such operations, acts, and/or functionsmay actually be performed by specific components or combinations ofcomponents of the UE 302, base station 304, network entity 306, etc.,such as the processors 332, 384, 394, the transceivers 310, 320, 350,and 360, the memories 340, 386, and 396, the positioning component 342,388, and 398, etc.

In some designs, the network entity 306 may be implemented as a corenetwork component. In other designs, the network entity 306 may bedistinct from a network operator or operation of the cellular networkinfrastructure (e.g., NG RAN 220 and/or 5GC 210/260). For example, thenetwork entity 306 may be a component of a private network that may beconfigured to communicate with the UE 302 via the base station 304 orindependently from the base station 304 (e.g., over a non-cellularcommunication link, such as WiFi).

Various frame structures may be used to support downlink and uplinktransmissions between network nodes (e.g., base stations and UEs). FIG.4A is a diagram 400 illustrating an example of a downlink framestructure, according to aspects of the disclosure. Other wirelesscommunications technologies may have different frame structures and/ordifferent channels.

LTE, and in some cases NR, utilizes OFDM on the downlink andsingle-carrier frequency division multiplexing (SC-FDM) on the uplink.Unlike LTE, however, NR has an option to use OFDM on the uplink as well.OFDM and SC-FDM partition the system bandwidth into multiple (K)orthogonal subcarriers, which are also commonly referred to as tones,bins, etc. Each subcarrier may be modulated with data. In general,modulation symbols are sent in the frequency domain with OFDM and in thetime domain with SC-FDM. The spacing between adjacent subcarriers may befixed, and the total number of subcarriers (K) may be dependent on thesystem bandwidth. For example, the spacing of the subcarriers may be 15kilohertz (kHz) and the minimum resource allocation (resource block) maybe 12 subcarriers (or 180 kHz). Consequently, the nominal FFT size maybe equal to 128, 256, 512, 1024, or 2048 for system bandwidth of 1.25,2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidthmay also be partitioned into subbands. For example, a subband may cover1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16subbands for system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz,respectively.

LTE supports a single numerology (subcarrier spacing (SCS), symbollength, etc.). In contrast, NR may support multiple numerologies (μ),for example, subcarrier spacings of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz(μ=2), 120 kHz (μ=3), and 240 kHz (μ=4) or greater may be available. Ineach subcarrier spacing, there are 14 symbols per slot. For 15 kHz SCS(μ=0), there is one slot per subframe, 10 slots per frame, the slotduration is 1 millisecond (ms), the symbol duration is 66.7 microseconds(μs), and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 50. For 30 kHz SCS (μ=1), there are two slots per subframe, 20slots per frame, the slot duration is 0.5 ms, the symbol duration is33.3 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 100. For 60 kHz SCS (μ=2), there are four slots per subframe, 40slots per frame, the slot duration is 0.25 ms, the symbol duration is16.7 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 200. For 120 kHz SCS (μ=3), there are eight slots per subframe,80 slots per frame, the slot duration is 0.125 ms, the symbol durationis 8.33 μs, and the maximum nominal system bandwidth (in MHz) with a 4KFFT size is 400. For 240 kHz SCS (μ=4), there are 16 slots per subframe,160 slots per frame, the slot duration is 0.0625 ms, the symbol durationis 4.17 μs, and the maximum nominal system bandwidth (in MHz) with a 4KFFT size is 800.

In the example of FIG. 4A, a numerology of 15 kHz is used. Thus, in thetime domain, a 10 ms frame is divided into 10 equally sized subframes of1 ms each, and each subframe includes one time slot. In FIG. 4A, time isrepresented horizontally (on the X axis) with time increasing from leftto right, while frequency is represented vertically (on the Y axis) withfrequency increasing (or decreasing) from bottom to top.

A resource grid may be used to represent time slots, each time slotincluding one or more time-concurrent resource blocks (RBs) (alsoreferred to as physical RBs (PRBs)) in the frequency domain. Theresource grid is further divided into multiple resource elements (REs).An RE may correspond to one symbol length in the time domain and onesubcarrier in the frequency domain. In the numerology of FIG. 4A, for anormal cyclic prefix, an RB may contain 12 consecutive subcarriers inthe frequency domain and seven consecutive symbols in the time domain,for a total of 84 REs. For an extended cyclic prefix, an RB may contain12 consecutive subcarriers in the frequency domain and six consecutivesymbols in the time domain, for a total of 72 REs. The number of bitscarried by each RE depends on the modulation scheme.

Some of the REs carry downlink reference (pilot) signals (DL-RS). TheDL-RS may include positioning reference signals (PRS), trackingreference signals (TRS), phase tracking reference signals (PTRS),cell-specific reference signals (CRS), channel state informationreference signals (CSI-RS), demodulation reference signals (DMRS),primary synchronization signals (PSS), secondary synchronization signals(SSS), synchronization signal blocks (SSBs), etc. FIG. 4A illustratesexample locations of REs carrying PRS (labeled “R”).

A collection of resource elements (REs) that are used for transmissionof PRS is referred to as a “PRS resource.” The collection of resourceelements can span multiple PRBs in the frequency domain and ‘N’ (such as1 or more) consecutive symbol(s) within a slot in the time domain. In agiven OFDM symbol in the time domain, a PRS resource occupiesconsecutive PRBs in the frequency domain.

The transmission of a PRS resource within a given PRB has a particularcomb size (also referred to as the “comb density”). A comb size ‘N’represents the subcarrier spacing (or frequency/tone spacing) withineach symbol of a PRS resource configuration. Specifically, for a combsize ‘N,’ PRS are transmitted in every Nth subcarrier of a symbol of aPRB. For example, for comb-4, for each symbol of the PRS resourceconfiguration, REs corresponding to every fourth subcarrier (such assubcarriers 0, 4, 8) are used to transmit PRS of the PRS resource.Currently, comb sizes of comb-2, comb-4, comb-6, and comb-12 aresupported for DL-PRS. FIG. 4A illustrates an example PRS resourceconfiguration for comb-6 (which spans six symbols). That is, thelocations of the shaded REs (labeled “R”) indicate a comb-6 PRS resourceconfiguration.

Currently, a DL-PRS resource may span 2, 4, 6, or 12 consecutive symbolswithin a slot with a fully frequency-domain staggered pattern. A DL-PRSresource can be configured in any higher layer configured downlink orflexible (FL) symbol of a slot. There may be a constant energy perresource element (EPRE) for all REs of a given DL-PRS resource. Thefollowing are the frequency offsets from symbol to symbol for comb sizes2, 4, 6, and 12 over 2, 4, 6, and 12 symbols. 2-symbol comb-2: {0, 1};4-symbol comb-2: {0, 1, 0, 1}; 6-symbol comb-2: {0, 1, 0, 1, 0, 1};12-symbol comb-2: {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1}; 4-symbol comb-4:{0, 2, 1, 3}; 12-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3};6-symbol comb-6: {0, 3, 1, 4, 2, 5}; 12-symbol comb-6: {0, 3, 1, 4, 2,5, 0, 3, 1, 4, 2, 5}; and 12-symbol comb-12: {0, 6, 3, 9, 1, 7, 4, 10,2, 8, 5, 11}.

A “PRS resource set” is a set of PRS resources used for the transmissionof PRS signals, where each PRS resource has a PRS resource ID. Inaddition, the PRS resources in a PRS resource set are associated withthe same TRP. A PRS resource set is identified by a PRS resource set IDand is associated with a particular TRP (identified by a TRP ID). Inaddition, the PRS resources in a PRS resource set have the sameperiodicity, a common muting pattern configuration, and the samerepetition factor (such as “PRS-ResourceRepetitionFactor”) across slots.The periodicity is the time from the first repetition of the first PRSresource of a first PRS instance to the same first repetition of thesame first PRS resource of the next PRS instance. The periodicity mayhave a length selected from 2{circumflex over ( )}μ*{4, 5, 8, 10, 16,20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} slots, withμ=0, 1, 2, 3. The repetition factor may have a length selected from {1,2, 4, 6, 8, 16, 32} slots.

A PRS resource ID in a PRS resource set is associated with a single beam(or beam ID) transmitted from a single TRP (where a TRP may transmit oneor more beams). That is, each PRS resource of a PRS resource set may betransmitted on a different beam, and as such, a “PRS resource,” orsimply “resource,” also can be referred to as a “beam.” Note that thisdoes not have any implications on whether the TRPs and the beams onwhich PRS are transmitted are known to the UE.

A “PRS instance” or “PRS occasion” is one instance of a periodicallyrepeated time window (such as a group of one or more consecutive slots)where PRS are expected to be transmitted. A PRS occasion also may bereferred to as a “PRS positioning occasion,” a “PRS positioninginstance, a “positioning occasion,” “a positioning instance,” a“positioning repetition,” or simply an “occasion,” an “instance,” or a“repetition.”

A “positioning frequency layer” (also referred to simply as a “frequencylayer”) is a collection of one or more PRS resource sets across one ormore TRPs that have the same values for certain parameters.Specifically, the collection of PRS resource sets has the samesubcarrier spacing and cyclic prefix (CP) type (meaning all numerologiessupported for the PDSCH are also supported for PRS), the same Point A,the same value of the downlink PRS bandwidth, the same start PRB (andcenter frequency), and the same comb-size. The Point A parameter takesthe value of the parameter “ARFCN-ValueNR” (where “ARFCN” stands for“absolute radio-frequency channel number”) and is an identifier/codethat specifies a pair of physical radio channel used for transmissionand reception. The downlink PRS bandwidth may have a granularity of fourPRBs, with a minimum of 24 PRBs and a maximum of 272 PRBs. Currently, upto four frequency layers have been defined, and up to two PRS resourcesets may be configured per TRP per frequency layer.

The concept of a frequency layer is somewhat like the concept ofcomponent carriers and bandwidth parts (BWPs), but different in thatcomponent carriers and BWPs are used by one base station (or a macrocell base station and a small cell base station) to transmit datachannels, while frequency layers are used by several (usually three ormore) base stations to transmit PRS. A UE may indicate the number offrequency layers it can support when it sends the network itspositioning capabilities, such as during an LTE positioning protocol(LPP) session. For example, a UE may indicate whether it can support oneor four positioning frequency layers.

FIG. 4B is a diagram 450 illustrating an example uplink frame structure.In FIG. 4B, time is represented horizontally (on the X axis) with timeincreasing from left to right, while frequency is represented vertically(on the Y axis) with frequency increasing (or decreasing) from bottom totop. In the example of FIG. 4B, a numerology of 15 kHz is used.

As illustrated in FIG. 4B, some of the REs (labeled “R”) carrydemodulation reference signals (DMRS) for channel estimation at thereceiver (e.g., a base station, another UE, etc.). A UE may additionallytransmit SRS in, for example, the last symbol of a slot. The SRS mayhave a comb structure, and a UE may transmit SRS on one of the combs. Inthe example of FIG. 4B, the illustrated SRS is comb-2 over one symbol.The SRS may be used by a base station to obtain the channel stateinformation (CSI) for each UE. CSI describes how an RF signal propagatesfrom the UE to the base station and represents the combined effect ofscattering, fading, and power decay with distance. The system uses theSRS for resource scheduling, link adaptation, massive MIMO, beammanagement, etc.

Currently, an SRS resource may span 1, 2, 4, 8, or 12 consecutivesymbols within a slot with a comb size of comb-2, comb-4, or comb-8. Thefollowing are the frequency offsets from symbol to symbol for the SRScomb patterns that are currently supported. 1-symbol comb-2: {0};2-symbol comb-2: {0, 1}; 4-symbol comb-2: {0, 1, 0, 1}; 4-symbol comb-4:{0, 2, 1, 3}; 8-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3}; 12-symbolcomb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3}; 4-symbol comb-8: {0, 4, 2,6}; 8-symbol comb-8: {0, 4, 2, 6, 1, 5, 3, 7}; and 12-symbol comb-8: {0,4, 2, 6, 1, 5, 3, 7, 0, 4, 2, 6}.

A collection of resource elements that are used for transmission of SRSis referred to as an “SRS resource,” and may be identified by theparameter “SRS-ResourceId.” The collection of resource elements can spanmultiple PRBs in the frequency domain and N (e.g., one or more)consecutive symbol(s) within a slot in the time domain. In a given OFDMsymbol, an SRS resource occupies consecutive PRBs. An “SRS resource set”is a set of SRS resources used for the transmission of SRS signals, andis identified by an SRS resource set ID (“SRS-ResourceSetId”).

Generally, a UE transmits SRS to enable the receiving base station(either the serving base station or a neighboring base station) tomeasure the channel quality between the UE and the base station.However, SRS can also be specifically configured as uplink positioningreference signals for uplink-based positioning procedures, such asuplink time difference of arrival (UL-TDOA), round-trip-time (RTT),uplink angle-of-arrival (UL-AoA), etc. As used herein, the term “SRS”may refer to SRS configured for channel quality measurements or SRSconfigured for positioning purposes. The former may be referred toherein as “SRS-for-communication” and/or the latter may be referred toas “SRS-for-positioning” when needed to distinguish the two types ofSRS.

Several enhancements over the previous definition of SRS have beenproposed for SRS-for-positioning (also referred to as “UL-PRS”), such asa new staggered pattern within an SRS resource (except forsingle-symbol/comb-2), a new comb type for SRS, new sequences for SRS, ahigher number of SRS resource sets per component carrier, and a highernumber of SRS resources per component carrier. In addition, theparameters “SpatialRelationInfo” and “PathLossReference” are to beconfigured based on a downlink reference signal or SSB from aneighboring TRP. Further still, one SRS resource may be transmittedoutside the active BWP, and one SRS resource may span across multiplecomponent carriers. Also, SRS may be configured in RRC connected stateand only transmitted within an active BWP. Further, there may be nofrequency hopping, no repetition factor, a single antenna port, and newlengths for SRS (e.g., 8 and 12 symbols). There also may be open-looppower control and not closed-loop power control, and comb-8 (i.e., anSRS transmitted every eighth subcarrier in the same symbol) may be used.Lastly, the UE may transmit through the same transmit beam from multipleSRS resources for UL-AoA. All of these are features that are additionalto the current SRS framework, which is configured through RRC higherlayer signaling (and potentially triggered or activated through MACcontrol element (CE) or DCI).

Note that the terms “positioning reference signal” and “PRS” generallyrefer to specific reference signals that are used for positioning in NRand LTE systems. However, as used herein, the terms “positioningreference signal” and “PRS” may also refer to any type of referencesignal that can be used for positioning, such as but not limited to, PRSas defined in LTE and NR, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB,SRS, UL-PRS, etc. In addition, the terms “positioning reference signal”and “PRS” may refer to downlink or uplink positioning reference signals,unless otherwise indicated by the context. If needed to furtherdistinguish the type of PRS, a downlink positioning reference signal maybe referred to as a “DL-PRS,” and an uplink positioning reference signal(e.g., an SRS-for-positioning, PTRS) may be referred to as an “UL-PRS.”In addition, for signals that may be transmitted in both the uplink anddownlink (e.g., DMRS, PTRS), the signals may be prepended with “UL” or“DL” to distinguish the direction. For example, “UL-DMRS” may bedifferentiated from “DL-DMRS.”

NR supports a number of cellular network-based positioning technologies,including downlink-based, uplink-based, and downlink-and-uplink-basedpositioning methods. Downlink-based positioning methods include observedtime difference of arrival (OTDOA) in LTE, downlink time difference ofarrival (DL-TDOA) in NR, and downlink angle-of-departure (DL-AoD) in NR.In an OTDOA or DL-TDOA positioning procedure, a UE measures thedifferences between the times of arrival (ToAs) of reference signals(e.g., positioning reference signals (PRS)) received from pairs of basestations, referred to as reference signal time difference (RSTD) or timedifference of arrival (TDOA) measurements, and reports them to apositioning entity. More specifically, the UE receives the identifiers(IDs) of a reference base station (e.g., a serving base station) andmultiple non-reference base stations in assistance data. The UE thenmeasures the RSTD between the reference base station and each of thenon-reference base stations. Based on the known locations of theinvolved base stations and the RSTD measurements, the positioning entitycan estimate the UE's location.

For DL-AoD positioning, the positioning entity uses a beam report fromthe UE of received signal strength measurements of multiple downlinktransmit beams to determine the angle(s) between the UE and thetransmitting base station(s). The positioning entity can then estimatethe location of the UE based on the determined angle(s) and the knownlocation(s) of the transmitting base station(s).

Uplink-based positioning methods include uplink time difference ofarrival (UL-TDOA) and uplink angle-of-arrival (UL-AoA). UL-TDOA issimilar to DL-TDOA, but is based on uplink reference signals (e.g.,sounding reference signals (SRS)) transmitted by the UE. For UL-AoApositioning, one or more base stations measure the received signalstrength of one or more uplink reference signals (e.g., SRS) receivedfrom a UE on one or more uplink receive beams. The positioning entityuses the signal strength measurements and the angle(s) of the receivebeam(s) to determine the angle(s) between the UE and the basestation(s). Based on the determined angle(s) and the known location(s)of the base station(s), the positioning entity can then estimate thelocation of the UE.

Downlink-and-uplink-based positioning methods include enhanced cell-ID(E-CID) positioning and multi-round-trip-time (RTT) positioning (alsoreferred to as “multi-cell RTT”). In an RTT procedure, an initiator (abase station or a UE) transmits an RTT measurement signal (e.g., a PRSor SRS) to a responder (a UE or base station), which transmits an RTTresponse signal (e.g., an SRS or PRS) back to the initiator. The RTTresponse signal includes the difference between the ToA of the RTTmeasurement signal and the transmission time of the RTT response signal,referred to as the reception-to-transmission (Rx-Tx) time difference.The initiator calculates the difference between the transmission time ofthe RTT measurement signal and the ToA of the RTT response signal,referred to as the transmission-to-reception (Tx-Rx) time difference.The propagation time (also referred to as the “time of flight”) betweenthe initiator and the responder can be calculated from the Tx-Rx andRx-Tx time differences. Based on the propagation time and the knownspeed of light, the distance between the initiator and the responder canbe determined. For multi-RTT positioning, a UE performs an RTT procedurewith multiple base stations to enable its location to be determined(e.g., using multilateration) based on the known locations of the basestations. RTT and multi-RTT methods can be combined with otherpositioning techniques, such as UL-AoA and DL-AoD, to improve locationaccuracy.

The E-CID positioning method is based on radio resource management (RRM)measurements. In E-CID, the UE reports the serving cell ID, the timingadvance (TA), and the identifiers, estimated timing, and signal strengthof detected neighbor base stations. The location of the UE is thenestimated based on this information and the known locations of the basestation(s).

To assist positioning operations, a location server (e.g., locationserver 230, LMF 270, SLP 272) may provide assistance data to the UE. Forexample, the assistance data may include identifiers of the basestations (or the cells/TRPs of the base stations) from which to measurereference signals, the reference signal configuration parameters (e.g.,the number of consecutive positioning subframes, periodicity ofpositioning subframes, muting sequence, frequency hopping sequence,reference signal identifier, reference signal bandwidth, etc.), and/orother parameters applicable to the particular positioning method.Alternatively, the assistance data may originate directly from the basestations themselves (e.g., in periodically broadcasted overheadmessages, etc.). In some cases, the UE may be able to detect neighbornetwork nodes itself without the use of assistance data.

In the case of an OTDOA or DL-TDOA positioning procedure, the assistancedata may further include an expected RSTD value and an associateduncertainty, or search window, around the expected RSTD. In some cases,the value range of the expected RSTD may be +/−500 microseconds (μs). Insome cases, when any of the resources used for the positioningmeasurement are in FR1, the value range for the uncertainty of theexpected RSTD may be +/−32 μs. In other cases, when all of the resourcesused for the positioning measurement(s) are in FR2, the value range forthe uncertainty of the expected RSTD may be +/−8 μs.

A location estimate may be referred to by other names, such as aposition estimate, location, position, position fix, fix, or the like. Alocation estimate may be geodetic and comprise coordinates (e.g.,latitude, longitude, and possibly altitude) or may be civic and comprisea street address, postal address, or some other verbal description of alocation. A location estimate may further be defined relative to someother known location or defined in absolute terms (e.g., using latitude,longitude, and possibly altitude). A location estimate may include anexpected error or uncertainty (e.g., by including an area or volumewithin which the location is expected to be included with some specifiedor default level of confidence).

FIG. 5 illustrates an example wireless communications system 500,according to aspects of the disclosure. In the example of FIG. 5 , a UE504 (e.g., any of the UEs described herein) is attempting to calculatean estimate of its position, or to assist another entity (e.g., a basestation or core network component, another UE, a location server, athird party application, etc.) to calculate an estimate of its position.The UE 504 may communicate wirelessly with a base station 502 (e.g., anyof the base stations described herein) using RF signals and standardizedprotocols for the modulation of the RF signals and the exchange ofinformation packets.

As illustrated in FIG. 5 , the base station 502 is utilizing beamformingto transmit a plurality of beams 511-515 of RF signals. Each beam511-515 may be formed and transmitted by an array of antennas of thebase station 502. Although FIG. 5 illustrates a base station 502transmitting five beams, as will be appreciated, there may be more orfewer than five beams, beam shapes such as peak gain, width, andside-lobe gains may differ amongst the transmitted beams, and some ofthe beams may be transmitted by a different base station.

A beam index may be assigned to each of the plurality of beams 511-515for purposes of distinguishing RF signals associated with one beam fromRF signals associated with another beam. Moreover, the RF signalsassociated with a particular beam of the plurality of beams 511-515 maycarry a beam index indicator. A beam index may also be derived from thetime of transmission, e.g., frame, slot, and/or OFDM symbol number, ofthe RF signal. The beam index indicator may be, for example, a three-bitfield for uniquely distinguishing up to eight beams. If two different RFsignals having different beam indices are received, this would indicatethat the RF signals were transmitted using different beams. If twodifferent RF signals share a common beam index, this would indicate thatthe different RF signals are transmitted using the same beam. Anotherway to describe that two RF signals are transmitted using the same beamis to say that the antenna port(s) used for the transmission of thefirst RF signal are spatially quasi-collocated with the antenna port(s)used for the transmission of the second RF signal.

In the example of FIG. 5 , the UE 504 receives a non-line-of-sight(NLOS) data stream 523 of RF signals transmitted on beam 513 and aline-of-sight (LOS) data stream 524 of RF signals transmitted on beam514. Although FIG. 5 illustrates the NLOS data stream 523 and the LOSdata stream 524 as single lines (dashed and solid, respectively), aswill be appreciated, the NLOS data stream 523 and the LOS data stream524 may each comprise multiple rays by the time they reach the UE 504due, for example, to the propagation characteristics of RF signalsthrough multipath channels. For example, a cluster of RF signals isformed when an electromagnetic wave is reflected off of multiplesurfaces of an object, and reflections arrive at the receiver (e.g., UE504) from roughly the same angle, each travelling a few wavelengths(e.g., centimeters) more or less than others. The receiverdetects/measures clusters of channel taps, each channel tap generallycorresponding to a ray and each cluster generally corresponding to asingle transmitted RF signal (e.g., NLOS data stream 523 and the LOSdata stream 524). Each channel tap represents a multipath that the RFsignal followed between the transmitter and the receiver. That is, achannel tap represents the arrival of an RF signal on a multipath. Eachcluster of channel taps indicates that the corresponding multipathsfollowed essentially the same path. There may be different clusters dueto the RF signal being transmitted on different transmit beams (andtherefore at different angles), or because of the propagationcharacteristics of RF signals (e.g., potentially following differentpaths due to reflections), or both.

In the example of FIG. 5 , the NLOS data stream 523 is not originallydirected at the UE 504, although, as will be appreciated, it could be.However, it is reflected off a reflector 540 (e.g., a building) andreaches the UE 504 without obstruction, and therefore, may still be arelatively strong RF signal. In contrast, the LOS data stream 524 isdirected at the UE 504 but passes through an obstruction 530 (e.g.,vegetation, a building, a hill, a disruptive environment such as cloudsor smoke, etc.), which may significantly degrade the RF signal. As willbe appreciated, although the LOS data stream 524 is weaker than the NLOSdata stream 523, the LOS data stream 524 will arrive at the UE 504before the NLOS data stream 523 because it follows a shorter path fromthe base station 502 to the UE 504.

The beam of interest for data communication between a transmitter (e.g.,base station 502) and a receiver (e.g., UE 504) is the beam carrying RFsignals that arrives at the receiver with the highest signal strength(e.g., the highest RSRP or SINR), whereas the beam of interest forposition estimation is the beam carrying RF signals that excites the LOSpath and that has the highest gain along the LOS path amongst all otherbeams (e.g., beam 514). That is, even if beam 513 (the NLOS beam) wereto weakly excite the LOS path (due to the propagation characteristics ofRF signals, even though not being focused along the LOS path), that weaksignal, if any, of the LOS path of beam 513 may not be as reliablydetectable (compared to that from beam 514), thus leading to greatererror in performing a positioning measurement.

While the beam of interest for data communication and the beam ofinterest for position estimation may usually be the same beams for somefrequency bands, for other frequency bands, such as mmW, they may not bethe same beams. As such, referring to FIG. 5 , where the UE 504 isengaged in a data communication session with the base station 502 (e.g.,where the base station 502 is the serving base station for the UE 504)and not simply attempting to measure reference RF signals transmitted bythe base station 502, the beam of interest for the data communicationsession may be the beam 513, as it is carrying the unobstructed NLOSdata stream 523. The beam of interest for position estimation, however,would be the beam 514, as it carries the strongest LOS data stream 524,despite being obstructed.

FIG. 6 is a diagram of an example physical layer procedure 600 forprocessing PRS transmitted on multiple beams, according to aspects ofthe disclosure. At stage 610, the network (e.g., location server 230,LMF 270, SLP 272) configures a given base station (e.g., a gNB) totransmit beamformed PRS to one or more UEs in the coverage area(s) ofthe cell(s) supported by the base station. The PRS configuration mayinclude multiple instances of PRS to be beam swept across all AoDs foreach cell at full transmit power per beam. In the example of FIG. 6 ,the base station transmits PRS on a first beam (labeled “Beam 1”) at afirst time (labeled “Time=1”), a second beam (labeled “Beam 2”) at asecond time (labeled “Time=2”), and so on until an Nth beam (labeled“Beam N”) at an Nth time (labeled “Time=N”), where N is an integer from1 to 128 (i.e., there may be as many as 128 beams for a single cell).The illustrated beams may be for a particular cell supported by the basestation, and the base station may beam sweep PRS in each of the cells itsupports. The base station may beam sweep using a single antenna orantenna array, in which case, that antenna or antenna array transmitseach beam (Beams 1 to N). Alternatively, the base station may beam sweepusing multiple antennas or antenna arrays, in which case, each antennaor antenna array transmits one or more of Beams 1 to N.

At 620, a given UE monitors all cells that it has been configured by thenetwork to monitor and that are configured to transmit PRS across theconfigured instances. There may need to be several PRSinstances/occasions to permit the UE to detect a sufficient number ofcells for positioning (due to the time it takes the UE to tune its radiofrom one cell to another and then monitor the cell). The UE measures thechannel, in particular the channel energy response (CER) and ToA, acrossall cells for which the UE has been configured to search for PRS.

At 630, the UE prunes the CERs across the cells to determine the ToAs ofthe PRS beams. In estimating the ToA from the CER, an earliest arrivalpath (i.e., the LOS path) is determined using a noise-related qualitythreshold to eliminate spurious local peaks. A ToA estimate is chosensuch that it is the earliest local maximum of the CER. For example, aToA estimate may be chosen such that it is the earliest peak that is atleast some threshold ‘X’ dB higher than the median of the CER and is atmost some threshold ‘Y’ dB lower than the main peak.

At 640, the ToAs can be used to estimate the position of the UE using,for example, OTDOA/DL-TDOA, RTT, DL-AoD, etc. For example, the UE cancalculate RSTD or Rx-Tx measurements based on the ToAs of the PRS. TheUE can then estimate its location based on these measurements if it hasbeen provided with a base station almanac (BSA) that includes thephysical locations of the involved base stations. Alternatively, thenetwork can estimate the location of the UE if the UE reports the ToA(or RSTD, Rx-Tx time difference, etc.) measurements to the network.

FIG. 7 illustrates an example flow 700 for position estimation,according to aspects of the disclosure. At 710, the UE estimates theCERs from the PRSs transmitted by the involved TRPs/cells. At 720, theToAs are estimated by determining the earliest local maximum CERs. At730, the estimated ToAs are then pruned to derive the TDOA vector, whichmay include multiple ToA related measurements of multiple cells. TheTDOA vector is then used, at 740, to estimate the location of the UE(for UE-based positioning) or is reported to the network (forUE-assisted positioning).

Note that even at relatively high SINRs, there are occasions in whichthe ToA is wrongly estimated. One way to improve positioning accuracy isto select ToAs estimated from PRS transmitted from geographicallydispersed cells. In an aspect, ToA sorting and pruning techniques can beused to improve positioning accuracy by selecting the ToAs from thegeographically dispersed cells.

FIG. 8 illustrates an example flow 800 for selecting ToAs to improvepositioning accuracy, according to aspects of the disclosure. At 810,the UE can sort the ToAs based on one or more quality metrics of thecorresponding CERs. SINR (including signal-to-noise ratio (SNR)) is oneexample of a quality metric. Another example is the median-to-ToA peakratio. Yet another is the median-to-main peak ratio. At 820, the UE maythen prune the ToAs based on the quality metrics while at the same timeensuring that a sufficient number of geographically disperse TRPs/cellsare represented in the TDOA vector. In other words, the quality of thereceived PRS is not the sole criteria in selecting the ToAs for pruning.Rather, locations of the TRPs/cells are also taken into account whenchoosing the ToAs.

FIG. 9 is a diagram 900 of an example scenario for pruning ToAs,according to aspects of the disclosure. In the example of FIG. 9 , a UE904 can receive PRS from four cells supported by three base stations902. Specifically, the UE 904 can receive PRS from “Cell 1” and “Cell 2”supported by the same base station 902-1 (or anchor point), “Cell 3”supported by base station 902-2, and “Cell 4” supported by base station902-3. Because “Cell 1” and “Cell 2” are supported by the same basestation 902-1, they are referred to as being “co-sited” or as having thesame “anchor point.”

Based on measurements, the UE 904 may have determined that the qualitiesof the PRS are ordered, from best to worst, from “Cell 1,” “Cell 2,”“Cell 3,” and “Cell 4.” To estimate a 2D location of the UE 904 usingTDOA, at least three ToA measurements are needed. If the ToAs are chosenbased only on the quality metrics, then the three ToAs selected would bethe ToAs of the PRS from “Cell 1,” “Cell 2,” and “Cell 3.” However, theToAs of the PRS from “Cell 1,” “Cell 2,” and “Cell 3” may beinsufficient to determine a 2D location because “Cell 1” and “Cell 2”are co-sited, meaning that the UE 904 may not be able to differentiatethe ToAs of “Cell 1” and “Cell 2.” In this case, the ToA of the PRS from“Cell 2” (or “Cell 1”) may be pruned and the ToA of the PRS from “Cell4” may be included instead, assuming that the ToA of the PRS from “Cell4” meets the quality metric requirement.

In some cases, it is possible to include more than the minimum number ofToAs. For example, referring to FIG. 9 , the ToAs of PRS from both “Cell1” and “Cell 2” may be included as long as the ToAs of the PRS from“Cell 3” and “Cell 4” are also included in the TDOA vector. That is, inan aspect, the ToAs may be pruned so as to ensure that a sufficientnumber of geographically dispersed cells are represented in the prunedToAs (e.g., at least three non-co-sited cells for 2D positioning, atleast four non-co-sited cells for 3D positioning). As described furtherbelow, whether or not ToAs are of PRS from co-sited cells is but one ofseveral attributes that may be considered in pruning the ToAs.

Referring back to FIG. 8 , at 830, the UE may derive a TDOA vector fromthe pruned ToAs. For example, the ToA with the highest quality metricmay be identified as the reference ToA, and the RSTDs of otherTRPs/cells in the TDOA vector may be calculated in relation to thereference ToA.

In an aspect, a UE may be equipped to prune the ToAs as described abovewhen the network provides the UE with location attributes of the cells.In an aspect, these location attributes, or simply “attributes,” may berelative attributes, that is, relative to one another. For example, thesignaled attributes may not include any absolute location informationfor the cells, such as the x, y, z coordinates of the cells. The actualx, y, z coordinates would, however, be known to the location server.

The following are some (but not necessarily all) of the attributes ofthe cells that a UE may be provided: a co-site attribute, a lineattribute, an area boundary attribute, a height attribute, a heightboundary attribute, and a plane attribute. When a group of cells (e.g.,two or more cells) have the same co-site attribute, the member cells ofthe group are co-sited. When a group of cells have the same lineattribute, the member cells are on the same line. For example, themember cells may be on a line parallel to a train track. When a group ofcells have the same area boundary attribute, the member cells are alllocated within a threshold area boundary (e.g., within a thresholddistance of each other). When a group of cells have the same heightattribute, the member cells are all at the same height. When a group ofcells have the same height boundary attribute, the member cells are allwithin a threshold height boundary (e.g., within a threshold height ofeach other). When a group of cells have the same plane attribute, themember cells are all on the same 2D plane.

The signaling of the attributes from the network can be semi-static andcan be sent to the UE along with the PRS configuration, for example. Inone aspect, the signaling can take the form of collections of PRS IDs inwhich a common attribute (co-site, line, area boundary, height, heightboundary, plane) is identified with a particular PRS ID. The signalingcan be provided to the UE after the UE makes a request, after thenetwork is configured, or when the network configures a maximum size ofthe ToAs to be reported. Note that information related to height (e.g.,the height attribute, the height boundary attribute, the planeattribute) can be signaled if the network requires 3D positioning.

The network (e.g., location server, LMF 270, SLP 272) may signalattributes of a plurality of cells to the UE. In an aspect, theplurality of cells may be grouped into one or more cell groups, and eachcell group may comprise one or more member cells. Each cell group may beassociated with an attribute set comprising one or more attributes suchthat all member cells of the cell group have all attributes of theassociated attribute set in common.

In an aspect, the PRS ID may include a scrambling ID, and the attributeinformation may be embedded in the scrambling IDs of the PRS. The UE mayuse the scrambling ID of each PRS to identify the cell group to whichthe corresponding cell belongs. For example, for a scrambling ID of 16bits, the last two bits (e.g., bits 1 and 0) may be used for the co-siteattribute. In this example, if the scrambling IDs of two PRS have thesame last two bits, then it may be assumed that the two correspondingcells are co-sited. Conversely, if the last two bits are different, thenit may be assumed that the two cells are not co-sited, that is, arelocated at different sites. In this example, the last two bits aremapped to a co-site attribute type. As another example, bits ‘4’ to ‘2’may be used for the height attributes. For example, two cells with thesame values in bits ‘4’ to ‘2’ may be assumed to be at the same height.Conversely, two cells with different values in bits ‘4’ to ‘2’ may beassumed to be at different heights. In this example, the bits ‘4’ to ‘2’are mapped to a height attribute type.

Generally, if a specified set of bits of the scrambling ID is the samefor two or more cells, then those two or more cells belong to (i.e., aremember cells of) a cell group with a configured attribute. In an aspect,the bits of each scrambling ID may be divided into one or more attributebit ranges. Each attribute bit range may comprise one or more bits andmay be mapped to an attribute type (e.g., co-site attribute type, lineattribute type, area boundary attribute type, height attribute type,height boundary attribute type, plane attribute type, and so on). Foreach cell of the plurality of cells, each attribute of the cell may beencoded in the attribute bit range of the scrambling ID mapped to theattribute type of the attribute.

In another aspect, the attribute information may be embedded into theRRC configuration. The PRS may be configured with resource IDs. Also,different resource IDs may be associated with different attributes ofthe cells transmitting the PRS. For example, a UE may determine thatevery three resource IDs are co-sited. That is, cells transmitting PRSwith resource IDs ‘0’ to ‘2’ are member cells of a cell group co-sitedin one location, cells with resource IDs ‘3’ to ‘5’ are member cells ofa cell group co-sited in another location, and so on. Note that theactual x, y, z coordinates of the locations need not be provided to theUE.

As another example, the UE may determine that cells with resource IDs‘10’ to ‘15’ are member cells of a cell group at one height, cells withresource IDs ‘16’ to ‘20’ are member cells of a cell group at anotherheight, and so on. Again, the actual heights of the cells need not beknown to the UE. However, the network entity may inform the UE thatheights of member cells among different cell height groups differ fromeach other by at least a minimum group height differential.

Generally, the plurality of PRS may include a plurality of resource IDs.The plurality of resource IDs may be grouped into one or more resourceID groups, and each resource ID group may correspond to a cell group. Inother words, each resource ID group may correspond to an attribute setof one or more attributes as described above.

In an aspect, the UE may be configured with a default resource IDgrouping to associate different groups of resource IDs with differentattribute sets. Alternatively, or in addition thereto, the resource IDgroup information may be received from a network entity, such aslocation server 230, LMF 270, or SLP 272. For example, when the UEreceives the resource ID group information from the network, the UE mayoverwrite any previous resource ID group information.

FIG. 10 illustrates an example method 1000 for determining the locationof a UE, according to aspects of the disclosure. The method 1000 is anexample of a UE-assisted positioning method and involves a UE and anetwork entity (e.g., location server 230, LMF 270, SLP 272). At 1005,the network entity sends attribute and cell group information for aplurality of cells configured to transmit a corresponding plurality ofDL-PRS. For example, the information may be sent to the UE along withthe DL-PRS configuration for the involved cells. As mentioned above, theinformation may be sent as a result of a request from the UE, after anetwork configuration, or when the network configures a maximum size ofthe ToAs to be reported back to the network by the UE.

The attribute and cell group information may provide at least thefollowing information. The plurality of cells may be grouped into one ormore cell groups. Each cell group may comprise one or more member cells,in which each member cell is one of the plurality of cells. Each cellgroup may be associated with an attribute set comprising one or moreattributes (e.g., one or more of co-site, line, area boundary, height,height boundary, and plane). For each cell group, all member cells ofthe cell group should have all attributes of the associated attributeset in common. For example, if an attribute set of a cell group includesline and height attributes, then the UE may assume that all member cellsof the cell group are in the same line and are at the same height.

The plurality of DL-PRS transmitted by the plurality of cells includes aplurality of PRS IDs (e.g., scrambling ID, resource ID). In an aspect,the PRS IDs may correspond to the plurality of cells. For each cellgroup, the PRS ID of each member cell indicates a membership of thatcell in the cell group. For example, when scrambling IDs are used, thebit values of the attribute range of the scrambling ID for an attributeshould be the same for all member cells.

At 1010, the UE receives the attribute and cell group information. At1015, the network entity can configure the plurality of cells totransmit the plurality of DL-PRS. At 1020, the UE receives the pluralityof PRS from the plurality of cells. In addition, if configured (e.g., inthe case of an RTT positioning procedure), the UE also transmits UL-PRS(e.g., SRS).

At 1030, the UE determines the ToAs of the received plurality of PRS(e.g., one ToA per received/detected PRS). For example, for each PRS,the corresponding ToA may be determined such that it is the earliestlocal maximum of the CER meeting the threshold requirements (e.g., atleast some threshold dB higher than the median of the CER, and no morethan some threshold dB lower than the main peak of the CER). The UE mayalso determine the RSRP of the received plurality of DL-PRS and theRx-Tx time difference measurements of the received DL-PRS and thetransmitted UL-PRS (if configured for an RTT positioning procedure).

At 1040, the UE prunes the plurality of ToAs based on the attributeinformation. For example, the UE can sort the ToAs based on one or morequality metrics (e.g., estimated SINR or SNR, median-to-ToA-peak ratio,median-to-main peak ratio, etc.). The UE can then select one ToA foreach group of cells of the plurality of cells that has the highestquality metric, thereby pruning the remaining ToAs. For example, if theUE is configured with a co-site attribute for the plurality of cells,and therefore, the plurality of cells are grouped according to whetheror not they are located at the same site, the UE can select the highestquality ToA from each group of cells.

At 1050, the TDOA vector may be derived from the pruned ToAs. The UEsorts the ToAs such that the resulting TDOA vector includes ToA relatedmeasurements (e.g., ToAs, RSTDs) of multiple cells in which each cellrepresented in the TDOA vector is a cell of the plurality of cells.

Also, the cells represented in the TDOA vector should be sufficient todetermine a location of the UE in at least two dimensions. For example,the ToA pruning may be such that the TDOA vector includes ToA relatedmeasurements from at least three cells that are not co-sited with eachother. In other words, the TDOA should represent at least three cellswith different co-site attributes. This ensures that the ToAs of PRSfrom a sufficient number (e.g., above some threshold) of geographicallydispersed cells are taken into account for a 2D location determination.Of course, if the network allows, more than three ToA relatedmeasurements may be included. Additional measurements can help to reducethe uncertainties.

If cell groups with different line attributes are included, then in anaspect, positioning accuracy may be enhanced by pruning the ToAs suchthat the TDOA vector represents multiple (at least two) cells withdifferent line attributes. If cell groups with different area boundaryattributes are included, then in an aspect, positioning accuracy may beenhanced by pruning the ToAs such that the TDOA vector representsmultiple cells with different area boundary attributes.

If a three-dimensional location of the UE is desired, then the TDOAvector should include ToA related measurements from at least fourgeographically dispersed cells. In an aspect, at least four cells thatare not co-sited with each other may be represented in the TDOA vector.In another aspect, two of the cells may be within a same boundary area,but at different heights. Of course, it is preferable that the cells arein different boundary areas and at different heights. That is, if cellgroups with different height attributes are included, then in an aspect,positioning accuracy may be enhanced by pruning the ToAs such that theTDOA vector represents multiple cells with different height attributes.Also, if cell groups with different plane attributes are included, thenin an aspect, positioning accuracy may be enhanced by pruning the ToAssuch that the TDOA vector represents multiple cells with different planeattributes. Again, if the network allows, more than four ToA relatedmeasurements may be included to reduce the uncertainties.

At 1060, the UE sends the TDOA vector to the network entity (e.g., thelocation server 230, LMF 270, SLP 272). At 1065, the network entityreceives the TDOA vector. At 1075, since the network entity may be awareof the x, y, z coordinates of the plurality of cells, the network entitydetermines or otherwise estimates the UE's location based on the TDOAvector.

As described above with reference to FIG. 9 , co-located cells provideonly one anchor point for positioning estimation. However, as describedabove with reference to FIG. 10 , cells can be grouped based on variousattributes and a UE can choose one cell (e.g., the cell providing thebest ToA) per group to report for positioning purposes. This providesvarious benefits, such as enabling a UE to select a more diverse set ofcells for positioning purposes. In addition, reporting the ToA of asingle cell per group can also reduce signaling overhead. Specifically,the UE may report one full ToA measurement (referred to as a baseline orrepresentative ToA measurement) for one cell (referred to as therepresentative cell) and the ToA measurements for the remaining cells asdifferentials of the full ToA measurement.

For example, in some cases, a UE may be configured to report the ToAsfor multiple cells within the same group (i.e., multiple cells havingthe same attribute, such as co-site attribute). In such cases, the UEcan report one full ToA measurement for a representative cell in eachgroup of cells and report the ToA measurements for the remaining cellsin the group as differential values of the full ToA measurement.Similarly, where the UE only reports one ToA measurement per group ofcells, the UE can report one full ToA measurement for a representativecell of one group of cells and differential ToA measurements for allrepresentative cells of the remaining groups of cells that wouldotherwise be reported as full ToA measurements. As yet another option,the UE may report one full ToA measurement for a representative cell ofone group of cells and differential ToA measurements for all other cellsof all other groups. In some cases, this reduction in signaling overheadmay be sufficient to enable the UE to transmit the entire measurementreport in uplink control information (UCI) on the physical uplinkcontrol channel (PUCCH) or in one or more MAC control elements(MAC-CEs).

As a specific example, a UE may be configured to measure (and optionallyreport) the ToAs of PRS transmitted by the cells within a group of threecells. This may result in ToA measurements referred to as “ToA1,”“ToA2,” and “ToA3.” Given that the UE is attempting to identify the LOSpath between itself and each measured cell, the UE may assume that theearliest significant peak on the channel energy response represents theToA of the LOS path. However, the calculated ToA might be earlier thanthe actual ToA of the LOS path due to channel noise (e.g., a spuriouspeak may be misidentified as the ToA). As such, it may be beneficial toreport the ToA measurements for the other cells in the group, as theymay be more accurate. Accordingly, the UE may report the ToA for arepresentative cell (or reference cell) of the group (e.g., “ToA1”) anddifferential ToAs for the remaining cells of the group (e.g., “ToA2” and“ToA3”). The representative ToA (or baseline ToA) may be reported with‘X’ bits and the other ToAs may be reported with ‘Y’ bits. Morespecifically, the difference between the representative ToA and theother ToAs may be calculated as, for example, “ToA2”−“ToA1”=“Delta1” and“ToA3”−“ToA1”=“Delta2.” The delta values (i.e., the differences betweenthe representative ToA and the other ToA measurements) may berepresented by ‘Y’ bits, where ‘Y’ is expected to be significantly lessthan ‘X.’ In this way, rather than comprising three sets of ‘X’ bits(one set of ‘X’ bits per ToA), the measurement report may include ‘X’bits plus two sets of ‘Y’ bits. Where ‘Y’ is less than ‘X,’ this willresult in a (potentially significant) reduction in the number of bits.

As will be appreciated, the same principle also applies to otherpositioning measurements, such as RSTD, AoA, AoD, and Rx-Tx timedifference measurements. This is because these measurements are expectedto have a fairly small variance among the cells in a group of cellssharing one or more of the attributes identified above. However, thereis no such expectation for RSRP measurements, as RSRP measurements, evenwithin a group of cells, may have a wider range of possible values andtherefore larger differentials between them. Thus, reportingdifferential RSRP values within a group of cells, or across groups ofcells, may not save overhead within the measurement report. As such, theUE may not be expected to report differential RSRP measurements.However, if the RSRP measurements are within a threshold difference ofeach other, the UE may report differential RSRP values within a group ofcells, or even across cells.

To configure a UE to report differential positioning measurements, newparameters may be defined in the RRC configuration or PRS configurationthat identifies the cells from which to measure PRS. One parameter mayindicate the type of the baseline (or representative or reference)positioning measurement to report. For example, this field may indicatethat the UE is to report a full measurement of the earliest ToA of agroup of cells, the minimum RSTD of a group of cells, or the largestRSTD of a group of cells.

Another parameter may indicate the quantization resolution of thedifferential positioning measurements. For example, for RSTDmeasurements, the differential resolution could be 0.1 nanoseconds (ns),0.2 ns. 0.5 ns, etc. Thus, the UE can report a differential RSTDmeasurement as a multiple of the differential resolution.

Another parameter may be the size of the differential positioningmeasurement (e.g., ‘Y’ bits). In an aspect, if the UE is configured toreport the smallest differential, then it means that all differentialvalues should be reported as positive values; there is no need to use abit to represent negative values, thereby saving an additional bit forthe sign bit.

Another parameter may be the maximum number ‘N’ of differentialpositioning measurements to report. This may be derived from the uplinkgrant. By default, ‘N’ can be greater than or equal to zero. If ‘N’ isset to zero, then only the baseline measurement would be reported pergroup.

Another parameter may be the criteria of differential positioningmeasurements to report. For example, the differential report may beselected based on ascending order, descending order, confidentialitylevel, or UE-based.

Another parameter may be the grouping criteria of positioningmeasurements across cell groups. That is, the UE may be configured toreport a baseline positioning measurement for a representative cell ofone group of cells and differential positioning measurements for theremaining cells of that group and all other cells of all other groupsrelative to the baseline measurement. Alternatively, the UE may beconfigured to report a baseline measurement for a representative cell ofeach group of cells and differential measurements for the remainingcells of each group. For example, if the difference between themeasurements across all cells of all groups is below some firstthreshold, then the UE can report a single baseline measurement for allgroups and differential measurements for all but the representativecell. Otherwise, the UE can report a baseline measurement for each groupof cells and differential measurements for remaining cells in eachgroup. Within each group, there may be another threshold to determine ifthe measurements of the cells in that group can be reporteddifferentially. In an aspect, where the UE reports a single baselinemeasurement for all groups of cells, the UE and the network (e.g.,serving base station, location server 230, LMF 270, SLP 272) candynamically configure a new group that comprises the cell groups thatwere previously configured based on attribute (e.g., same cell site).The dynamic report group configuration can be reported to the locationserver and/or the serving base station in a dynamic or semi-persistentmanner. The group information should be agreed upon between the UE andthe network. Otherwise, each report should embed the group information,but this uses additional bandwidth and is therefore less preferable.

FIG. 11 illustrates an example method 1100 of wireless positioning,according to aspects of the disclosure. In an aspect, the method 1100may be performed by a UE (e.g., any of the UEs described herein).

At 1110, the UE receives a plurality of DL-PRS transmitted by acorresponding plurality of cells, wherein the plurality of cells isgrouped into one or more groups, wherein each of the one or more groupsis associated with one or more attributes, and wherein each cell of eachof the one or more groups has the same values of the one or moreattributes. In an aspect, operation 1110 may be performed by the one ormore WWAN transceivers 310, the one or more processors 332, memory 340,and/or positioning component 342, any or all of which may be consideredmeans for performing this operation.

At 1120, the UE reports, to a positioning entity, at least one baselinepositioning measurement for at least one representative cell of at leastone group of the one or more groups based on DL-PRS transmitted by theat least one representative cell. In an aspect, operation 1120 may beperformed by the one or more WWAN transceivers 310, the one or moreprocessors 332, memory 340, and/or positioning component 342, any or allof which may be considered means for performing this operation.

At 1130, the UE reports, to the positioning entity, differentialpositioning measurements for cells (not necessarily only the remainingcells of the at least one group because, for CER or power delay profile(PDP) reporting, the first channel tap for one cell could be a referencefor subsequent taps for that cell) of the at least one group based onthe at least one baseline positioning measurement. In an aspect,operation 1130 may be performed by the one or more WWAN transceivers310, the one or more processors 332, memory 340, and/or positioningcomponent 342, any or all of which may be considered means forperforming this operation.

As will be appreciated, a technical advantage of the method 1100 isreduced overhead when signaling positioning measurements.

In the detailed description above it can be seen that different featuresare grouped together in examples. This manner of disclosure should notbe understood as an intention that the example clauses have morefeatures than are explicitly mentioned in each clause. Rather, thevarious aspects of the disclosure may include fewer than all features ofan individual example clause disclosed. Therefore, the following clausesshould hereby be deemed to be incorporated in the description, whereineach clause by itself can stand as a separate example. Although eachdependent clause can refer in the clauses to a specific combination withone of the other clauses, the aspect(s) of that dependent clause are notlimited to the specific combination. It will be appreciated that otherexample clauses can also include a combination of the dependent clauseaspect(s) with the subject matter of any other dependent clause orindependent clause or a combination of any feature with other dependentand independent clauses. The various aspects disclosed herein expresslyinclude these combinations, unless it is explicitly expressed or can bereadily inferred that a specific combination is not intended (e.g.,contradictory aspects, such as defining an element as both an insulatorand a conductor). Furthermore, it is also intended that aspects of aclause can be included in any other independent clause, even if theclause is not directly dependent on the independent clause.

Implementation examples are described in the following numbered clauses:

Clause 1. A method of wireless positioning performed by a user equipment(UE), comprising: receiving a plurality of positioning reference signals(PRS) transmitted by a corresponding plurality of cells, wherein theplurality of cells is grouped into one or more groups, wherein each ofthe one or more groups is associated with one or more attributes, andwherein each cell of each of the one or more groups has the same valuesof the one or more attributes; determining at least one baselinepositioning measurement for at least one representative cell of at leastone group of the one or more groups based on PRS transmitted by the atleast one representative cell; determining differential positioningmeasurements for remaining cells of at least the at least one groupbased on the at least one baseline positioning measurement; andreporting the at least one baseline positioning measurement and thedifferential positioning measurements to a positioning entity.

Clause 2. The method of clause 1, wherein the remaining cells of atleast the at least one group comprise all remaining cells of all of theone or more groups.

Clause 3. The method of clause 2, wherein the UE determines thedifferential positioning measurements for all remaining cells of all ofthe one or more groups based on a value of each the differentialpositioning measurements being less than a threshold.

Clause 4. The method of any of clauses 1 to 3, wherein: the at least onegroup comprises only one group, and the remaining cells of at least theat least one group comprise all remaining cells of only the at least onegroup.

Clause 5. The method of clause 4, wherein: the one or more groupscomprise a plurality of groups, the determining the at least onebaseline positioning measurement comprises determining a baselinepositioning measurement for a representative cell of each of theplurality of groups, the determining the differential positioningmeasurements comprises determining differential positioning measurementsfor remaining cells of each of the plurality of groups based on thebaseline positioning measurement for that group, and the reportingcomprises reporting each baseline positioning measurement and thedifferential positioning measurements to the positioning entity.

Clause 6. The method of clause 5, wherein the UE determines differentialpositioning measurements for each of the plurality of groups based onvalues of differential positioning measurements across the plurality ofgroups being greater than a threshold.

Clause 7. The method of any of clauses 1 to 6, wherein the one or moreattributes comprise: a co-site attribute indicating that all cells ineach of the one or more groups are co-sited, a line attribute indicatingthat all cells in each of the one or more groups are in a line, an areaboundary attribute indicating that all cells in each of the one or moregroups are within a threshold area boundary, a height attributeindicating that heights of all cells in each of the one or more groupsare within a threshold height difference of each other, a planeattribute indicating that all cells in each of the one or more groupsare on a two-dimensional (2D) plane, or any combination thereof.

Clause 8. The method of any of clauses 1 to 7, further comprising:receiving a configuration comprising one or more parameters indicatinghow the at least one baseline positioning measurement and thedifferential positioning measurements are to be reported.

Clause 9. The method of clause 8, wherein the one or more parameterscomprise: a type of the at least one baseline positioning measurement, aquantization resolution for the differential positioning measurements, abit length for each of the differential positioning measurements, amaximum number of differential positioning measurements per group of theone or more groups, a maximum number of differential positioningmeasurements across all of the one or more groups, a criterionindicating how to select the differential positioning measurements forall of the one or more groups relative to a single baseline positioningmeasurement, an indication of whether to report differential positioningmeasurements for all of the one or more groups relative to a singlebaseline positioning measurement or to report differential positioningmeasurements for each of the one or more groups relative to adifferential positioning measurement for that group, or any combinationthereof.

Clause 10. The method of clause 9, wherein the type of the baselinepositioning measurement comprises an earliest time of arrival (ToA)measurement of all PRS transmitted by the cells in the at least onegroup, a smallest reference signal time difference (RSTD) measurement ofall PRS transmitted by cells in the at least one group, or a largestRSTD measurement of all PRS transmitted by the cells in the at least onegroup.

Clause 11. The method of any of clauses 9 to 10, wherein thequantization resolution is an increment of time, and whereindifferential positioning measurements are expected to be reported asmultiples of the increment of time.

Clause 12. The method of any of clauses 9 to 11, wherein the bit lengthdoes not include a sign bit to indicate negative numbers.

Clause 13. The method of any of clauses 9 to 12, wherein the maximumnumber of differential positioning measurements per group of the one ormore groups is greater than or equal to zero.

Clause 14. The method of any of clauses 9 to 13, wherein the maximumnumber of differential positioning measurements across all of the one ormore groups is greater than or equal to zero.

Clause 15. The method of any of clauses 9 to 14, wherein the indicationcomprises a threshold.

Clause 16. The method of any of clauses 9 to 14, wherein the indicationcomprises a flag bit.

Clause 17. The method of any of clauses 8 to 16, wherein theconfiguration comprises a radio resource control configuration.

Clause 18. The method of any of clauses 8 to 16, wherein theconfiguration comprises a PRS configuration.

Clause 19. The method of any of clauses 1 to 18, wherein the UE reportsthe at least one baseline positioning measurement and the differentialpositioning measurements in uplink control information (UCI) or one ormore medium access control control elements (MAC-CEs).

Clause 20. The method of any of clauses 1 to 19, wherein the positioningentity comprises a serving base station or a location server.

Clause 21. An apparatus comprising a memory, at least one transceiver,and at least one processor communicatively coupled to the memory and theat least one transceiver, the memory, the at least one transceiver, andthe at least one processor configured to perform a method according toany of clauses 1 to 20.

Clause 22. An apparatus comprising means for performing a methodaccording to any of clauses 1 to 20.

Clause 23. A non-transitory computer-readable medium storingcomputer-executable instructions, the computer-executable comprising atleast one instruction for causing a computer or processor to perform amethod according to any of clauses 1 to 20.

Additional implementation examples are described in the followingnumbered clauses:

Clause 1. A method of wireless positioning performed by a user equipment(UE), comprising: receiving a plurality of downlink positioningreference signals (DL-PRS) transmitted by a corresponding plurality ofcells, wherein the plurality of cells is grouped into one or moregroups, wherein each of the one or more groups is associated with one ormore attributes, and wherein each cell of each of the one or more groupshas the same values of the one or more attributes; reporting, to apositioning entity, at least one baseline positioning measurement for atleast one representative cell of at least one group of the one or moregroups based on DL-PRS transmitted by the at least one representativecell; and reporting, to the positioning entity, differential positioningmeasurements for cells of the at least one group based on the at leastone baseline positioning measurement.

Clause 2. The method of clause 1, wherein the differential positioningmeasurements for the cells of the at least one group are reported basedon a value of each of the differential positioning measurements beingless than a threshold.

Clause 3. The method of any of clauses 1 to 2, wherein: the at least onegroup comprises only one group, and the cells of the at least one groupcomprise all remaining cells of only the at least one group.

Clause 4. The method of clause 3, wherein: the one or more groupscomprise a plurality of groups, reporting the at least one baselinepositioning measurement comprises reporting a baseline positioningmeasurement for a representative cell of each of the plurality ofgroups, reporting the differential positioning measurements comprisesreporting differential positioning measurements for cells of each of theplurality of groups based on the baseline positioning measurement forthat group.

Clause 5. The method of clause 4, further comprising: determiningdifferential positioning measurements for each of the plurality ofgroups based on values of differential positioning measurements acrossthe plurality of groups being greater than a threshold.

Clause 6. The method of any of clauses 1 to 5, wherein the one or moreattributes comprise: a co-site attribute indicating that all cells ineach of the one or more groups are co-sited, a line attribute indicatingthat all cells in each of the one or more groups are in a line, an areaboundary attribute indicating that all cells in each of the one or moregroups are within a threshold area boundary, a height attributeindicating that heights of all cells in each of the one or more groupsare within a threshold height difference of each other, a planeattribute indicating that all cells in each of the one or more groupsare on a two-dimensional (2D) plane, or any combination thereof.

Clause 7. The method of any of clauses 1 to 6, further comprising:receiving a configuration comprising one or more parameters indicatinghow the at least one baseline positioning measurement and thedifferential positioning measurements are to be reported.

Clause 8. The method of clause 7, wherein the one or more parameterscomprise: a type of the at least one baseline positioning measurement, aquantization resolution for the differential positioning measurements, abit length for each of the differential positioning measurements, amaximum number of differential positioning measurements per group of theone or more groups, a maximum number of differential positioningmeasurements across all of the one or more groups, a criterionindicating how to select differential positioning measurements for allof the one or more groups relative to a single baseline positioningmeasurement, an indication of whether to report differential positioningmeasurements for all of the one or more groups relative to a singlebaseline positioning measurement or to report differential positioningmeasurements for each of the one or more groups relative to adifferential positioning measurement for that group, or any combinationthereof.

Clause 9. The method of clause 8, wherein the type of the at least onebaseline positioning measurement comprises an earliest time of arrival(ToA) measurement of DL-PRS transmitted by the cells in the at least onegroup, a measurement based on the earliest ToA, a smallest referencesignal time difference (RSTD) measurement of DL-PRS transmitted by thecells in the at least one group, a largest RSTD measurement of DL-PRStransmitted by the cells in the at least one group, a smallestreception-to-transmission (Rx-Tx) time difference measurement associatedwith DL-PRS transmitted by the cells in the at least one group, alargest Rx-Tx time difference measurement associated with DL-PRStransmitted by the cells in the at least one group, a smallest referencesignal received power (RSRP) measurement of DL-PRS transmitted by thecells in the at least one group, or a largest RSRP measurement of DL-PRStransmitted by the cells in the at least one group.

Clause 10. The method of any of clauses 8 to 9, wherein: thequantization resolution is an increment of time, and differentialpositioning measurements are expected to be reported as multiples of theincrement of time.

Clause 11. The method of any of clauses 8 to 10, wherein the bit lengthdoes not include a sign bit to indicate negative numbers.

Clause 12. The method of any of clauses 8 to 11, wherein the maximumnumber of differential positioning measurements per group of the one ormore groups is greater than or equal to zero.

Clause 13. The method of any of clauses 8 to 12, wherein the maximumnumber of differential positioning measurements across all of the one ormore groups is greater than or equal to zero.

Clause 14. The method of any of clauses 8 to 13, wherein: the indicationcomprises a threshold, or the indication comprises a flag bit.

Clause 15. The method of any of clauses 7 to 14, wherein theconfiguration comprises a radio resource control (RRC) configuration.

Clause 16. The method of any of clauses 7 to 15, wherein theconfiguration comprises a DL-PRS configuration.

Clause 17. The method of any of clauses 1 to 16, further comprising:receiving a configuration for uplink positioning reference signals(UL-PRS); and transmitting the UL-PRS to the plurality of cells based onthe configuration.

Clause 18. The method of any of clauses 1 to 17, wherein the at leastone baseline positioning measurement and the differential positioningmeasurements are reported in uplink control information (UCI), one ormore medium access control control elements (MAC-CEs), one or more RRCmessages, or one or more Long-Term Evolution (LTE) positioning protocol(LPP) messages.

Clause 19. An apparatus comprising a memory, at least one transceiver,and at least one processor communicatively coupled to the memory and theat least one transceiver, the memory, the at least one transceiver, andthe at least one processor configured to perform a method according toany of clauses 1 to 18.

Clause 20. An apparatus comprising means for performing a methodaccording to any of clauses 1 to 18.

Clause 21. A non-transitory computer-readable medium storingcomputer-executable instructions, the computer-executable comprising atleast one instruction for causing a computer or processor to perform amethod according to any of clauses 1 to 18.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an ASIC, a field-programable gate array (FPGA), or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,for example, a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read-only memory (ROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An example storage medium is coupled to the processor such thatthe processor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal (e.g., UE). In thealternative, the processor and the storage medium may reside as discretecomponents in a user terminal.

In one or more example aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the aspects of the disclosuredescribed herein need not be performed in any particular order.Furthermore, although elements of the disclosure may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

What is claimed is:
 1. A method of wireless positioning performed by auser equipment (UE), comprising: receiving a plurality of downlinkpositioning reference signals (DL-PRS) transmitted by a correspondingplurality of cells, wherein the plurality of cells is grouped into oneor more groups, wherein each of the one or more groups is associatedwith one or more attributes, and wherein each cell of each of the one ormore groups has the same values of the one or more attributes;reporting, to a positioning entity, at least one baseline positioningmeasurement for at least one representative cell of at least one groupof the one or more groups based on DL-PRS transmitted by the at leastone representative cell; and reporting, to the positioning entity,differential positioning measurements for cells of the at least onegroup based on the at least one baseline positioning measurement.
 2. Themethod of claim 1, wherein the differential positioning measurements forthe cells of the at least one group are reported based on a value ofeach of the differential positioning measurements being less than athreshold.
 3. The method of claim 1, wherein: the at least one groupcomprises only one group, and the cells of the at least one groupcomprise all remaining cells of only the at least one group.
 4. Themethod of claim 3, wherein: the one or more groups comprise a pluralityof groups, reporting the at least one baseline positioning measurementcomprises reporting a baseline positioning measurement for arepresentative cell of each of the plurality of groups, reporting thedifferential positioning measurements comprises reporting differentialpositioning measurements for cells of each of the plurality of groupsbased on the baseline positioning measurement for that group.
 5. Themethod of claim 4, further comprising: determining differentialpositioning measurements for each of the plurality of groups based onvalues of differential positioning measurements across the plurality ofgroups being greater than a threshold.
 6. The method of claim 1, whereinthe one or more attributes comprise: a co-site attribute indicating thatall cells in each of the one or more groups are co-sited, a lineattribute indicating that all cells in each of the one or more groupsare in a line, an area boundary attribute indicating that all cells ineach of the one or more groups are within a threshold area boundary, aheight attribute indicating that heights of all cells in each of the oneor more groups are within a threshold height difference of each other, aplane attribute indicating that all cells in each of the one or moregroups are on a two-dimensional (2D) plane, or any combination thereof.7. The method of claim 1, further comprising: receiving a configurationcomprising one or more parameters indicating how the at least onebaseline positioning measurement and the differential positioningmeasurements are to be reported.
 8. The method of claim 7, wherein theone or more parameters comprise: a type of the at least one baselinepositioning measurement, a quantization resolution for the differentialpositioning measurements, a bit length for each of the differentialpositioning measurements, a maximum number of differential positioningmeasurements per group of the one or more groups, a maximum number ofdifferential positioning measurements across all of the one or moregroups, a criterion indicating how to select differential positioningmeasurements for all of the one or more groups relative to a singlebaseline positioning measurement, an indication of whether to reportdifferential positioning measurements for all of the one or more groupsrelative to a single baseline positioning measurement or to reportdifferential positioning measurements for each of the one or more groupsrelative to a differential positioning measurement for that group, orany combination thereof.
 9. The method of claim 8, wherein the type ofthe at least one baseline positioning measurement comprises an earliesttime of arrival (ToA) measurement of DL-PRS transmitted by the cells inthe at least one group, a measurement based on the earliest ToA, asmallest reference signal time difference (RSTD) measurement of DL-PRStransmitted by the cells in the at least one group, a largest RSTDmeasurement of DL-PRS transmitted by the cells in the at least onegroup, a smallest reception-to-transmission (Rx-Tx) time differencemeasurement associated with DL-PRS transmitted by the cells in the atleast one group, a largest Rx-Tx time difference measurement associatedwith DL-PRS transmitted by the cells in the at least one group, asmallest reference signal received power (RSRP) measurement of DL-PRStransmitted by the cells in the at least one group, or a largest RSRPmeasurement of DL-PRS transmitted by the cells in the at least onegroup.
 10. The method of claim 8, wherein: the quantization resolutionis an increment of time, and differential positioning measurements areexpected to be reported as multiples of the increment of time.
 11. Themethod of claim 8, wherein the bit length does not include a sign bit toindicate negative numbers.
 12. The method of claim 8, wherein themaximum number of differential positioning measurements per group of theone or more groups is greater than or equal to zero.
 13. The method ofclaim 8, wherein the maximum number of differential positioningmeasurements across all of the one or more groups is greater than orequal to zero.
 14. The method of claim 8, wherein: the indicationcomprises a threshold, or the indication comprises a flag bit.
 15. Themethod of claim 7, wherein the configuration comprises a radio resourcecontrol (RRC) configuration.
 16. The method of claim 7, wherein theconfiguration comprises a DL-PRS configuration.
 17. The method of claim1, further comprising: receiving a configuration for uplink positioningreference signals (UL-PRS); and transmitting the UL-PRS to the pluralityof cells based on the configuration.
 18. The method of claim 1, whereinthe at least one baseline positioning measurement and the differentialpositioning measurements are reported in uplink control information(UCI), one or more medium access control control elements (MAC-CEs), oneor more RRC messages, or one or more Long-Term Evolution (LTE)positioning protocol (LPP) messages.
 19. A user equipment (UE),comprising: a memory; at least one transceiver; and at least oneprocessor communicatively coupled to the memory and the at least onetransceiver, the at least one processor configured to: receive, via theat least one transceiver, a plurality of downlink positioning referencesignals (DL-PRS) transmitted by a corresponding plurality of cells,wherein the plurality of cells is grouped into one or more groups,wherein each of the one or more groups is associated with one or moreattributes, and wherein each cell of each of the one or more groups hasthe same values of the one or more attributes; report, to a positioningentity, at least one baseline positioning measurement for at least onerepresentative cell of at least one group of the one or more groupsbased on DL-PRS transmitted by the at least one representative cell; andreport, to the positioning entity, differential positioning measurementsfor cells of the at least one group based on the at least one baselinepositioning measurement.
 20. The UE of claim 19, wherein thedifferential positioning measurements for the cells of the at least onegroup are reported based on a value of each of the differentialpositioning measurements being less than a threshold.
 21. The UE ofclaim 19, wherein: the at least one group comprises only one group, andthe cells of the at least one group comprise all remaining cells of onlythe at least one group.
 22. The UE of claim 19, wherein the one or moreattributes comprise: a co-site attribute indicating that all cells ineach of the one or more groups are co-sited, a line attribute indicatingthat all cells in each of the one or more groups are in a line, an areaboundary attribute indicating that all cells in each of the one or moregroups are within a threshold area boundary, a height attributeindicating that heights of all cells in each of the one or more groupsare within a threshold height difference of each other, a planeattribute indicating that all cells in each of the one or more groupsare on a two-dimensional (2D) plane, or any combination thereof.
 23. TheUE of claim 19, wherein the at least one processor is further configuredto: receive, via the at least one transceiver, a configurationcomprising one or more parameters indicating how the at least onebaseline positioning measurement and the differential positioningmeasurements are to be reported.
 24. The UE of claim 23, wherein the oneor more parameters comprise: a type of the at least one baselinepositioning measurement, a quantization resolution for the differentialpositioning measurements, a bit length for each of the differentialpositioning measurements, a maximum number of differential positioningmeasurements per group of the one or more groups, a maximum number ofdifferential positioning measurements across all of the one or moregroups, a criterion indicating how to select differential positioningmeasurements for all of the one or more groups relative to a singlebaseline positioning measurement, an indication of whether to reportdifferential positioning measurements for all of the one or more groupsrelative to a single baseline positioning measurement or to reportdifferential positioning measurements for each of the one or more groupsrelative to a differential positioning measurement for that group, orany combination thereof.
 25. The UE of claim 23, wherein theconfiguration comprises a radio resource control (RRC) configuration.26. The UE of claim 23, wherein the configuration comprises a DL-PRSconfiguration.
 27. The UE of claim 19, wherein the at least oneprocessor is further configured to: receive, via the at least onetransceiver, a configuration for uplink positioning reference signals(UL-PRS); and transmit, via the at least one transceiver, the UL-PRS tothe plurality of cells based on the configuration.
 28. The UE of claim19, wherein the at least one baseline positioning measurement and thedifferential positioning measurements are reported in uplink controlinformation (UCI), one or more medium access control control elements(MAC-CEs), one or more RRC messages, or one or more Long-Term Evolution(LTE) positioning protocol (LPP) messages.
 29. A user equipment (UE),comprising: means for receiving a plurality of downlink positioningreference signals (DL-PRS) transmitted by a corresponding plurality ofcells, wherein the plurality of cells is grouped into one or moregroups, wherein each of the one or more groups is associated with one ormore attributes, and wherein each cell of each of the one or more groupshas the same values of the one or more attributes; means for reporting,to a positioning entity, at least one baseline positioning measurementfor at least one representative cell of at least one group of the one ormore groups based on DL-PRS transmitted by the at least onerepresentative cell; and means for reporting, to the positioning entity,differential positioning measurements for cells of the at least onegroup based on the at least one baseline positioning measurement.
 30. Anon-transitory computer-readable medium storing computer-executableinstructions that, when executed by a user equipment (UE), cause the UEto: receive a plurality of downlink positioning reference signals(DL-PRS) transmitted by a corresponding plurality of cells, wherein theplurality of cells is grouped into one or more groups, wherein each ofthe one or more groups is associated with one or more attributes, andwherein each cell of each of the one or more groups has the same valuesof the one or more attributes; report, to a positioning entity, at leastone baseline positioning measurement for at least one representativecell of at least one group of the one or more groups based on DL-PRStransmitted by the at least one representative cell; and report, to thepositioning entity, differential positioning measurements for cells ofthe at least one group based on the at least one baseline positioningmeasurement.